London Amsterdam

6 nonstop pairs · 4 nonstop airlines · 545 nonstop flights/week

London to Amsterdam is barely an hour in the air, served from four London airports. The real question is whether you should fly at all.

If you are near Heathrow, BA and KLM split the schedule all day. KLM if you are connecting through Schiphol, BA if you collect Avios.

easyJet flies from Gatwick, Luton, and Stansted at lower fares. Luton and Stansted tend to be cheapest, but getting to those airports adds time and cost that can eat the saving.

If you are starting in central London, take the Eurostar from St Pancras. Four hours to Amsterdam Centraal, no airport on either end. The flight is shorter in the air, but once you add the trip to Heathrow, security, and the Schiphol-to-city train, door-to-door time is about the same.

The return Eurostar now runs direct without the old Brussels passport control stop. Both directions are nonstop.

If you do fly, trains from Schiphol to Centraal leave every 10 minutes and take 15. You walk off the plane and into the city faster than almost any airport in Europe.

Have a specific need? Use the decision guide below to filter by your airline, where you live, lounges, or where you're staying in Amsterdam.

Best Overall
LHR AMS
2 airlines 367/wk 1h 20m
British Airways, KLM. Also bookable via LATAM Chile. Eurostar from St Pancras to Amsterdam Centraal, four hours with no airport on either end.
Explore LHR → AMS
Strong Alternative
LCY → AMS
1 airline · 94/wk · 1h 05m
KLM. Also bookable via British Airways. KLM from Heathrow when the Eurostar does not fit your schedule, with fast Schiphol connections onward if Amsterdam is not the final stop.
London → Amsterdam 1 airline · 35/wk · 1h20m · easyJet from Gatwick, 30 miles south of central London. Gatwick Express to Victoria in around 30 minutes. Good Luton, Luton → Amsterdam 1 airline · 33/wk · 1h10m · easyJet from Luton, 32 miles north. Thameslink to St Pancras in around 25 minutes. Good London, Essex → Amsterdam 1 airline · 11/wk · 1h05m · Stansted is 36 miles northeast. Stansted Express reaches Liverpool Street in around 45 minutes. Good London Southend → Amsterdam 1 airline · 5/wk · 1h05m Limited
Nearby cities with nonstop service
~112mi Birmingham, West Midlands → Amsterdam 2 airlines · 154/wk Nearby ~111mi Bristol → Amsterdam 2 airlines · 90/wk Nearby ~53mi Southampton → Amsterdam 2 airlines · 28/wk Nearby
Nearby cities · connections only
~76mi Bournemouth No nonstop to Amsterdam Connecting

Pick What Matters to You

Show me the best pair for...

Best pair by where you're coming from

Your location determines which airport is closest and most convenient.
Westminster and the West End Best
Heathrow is the airport. The Elizabeth Line from Paddington takes around 30 minutes and runs frequently. The Piccadilly Line is slower at about 50 minutes but stops at more central stations along the way. From Soho, Covent Garden, or Mayfair, you are at Heathrow check-in in under an hour.
Kensington, Chelsea, and West London Best
Heathrow again. Piccadilly Line from Earl's Court or Gloucester Road in about 40 minutes. Paddington is one Tube stop from Bayswater and a short taxi from most of west London. The Elizabeth Line from Paddington is the fastest route to any terminal.
The City and Canary Wharf Best
London City Airport is six miles from the Square Mile and connected by DLR. Bank station to the terminal takes around 20 minutes. For other airports, the Elizabeth Line runs from Liverpool Street to Heathrow without changing trains.
Shoreditch, Hackney, and East London
Stansted Express from Liverpool Street in 47 minutes. Liverpool Street is a short bus or bike from most of east London. London City is also close on the DLR from Stratford or Limehouse. Heathrow is over an hour on the Elizabeth Line from here.
South London, Brixton, and Croydon Good
Gatwick is closer than Heathrow from anything south of the river. Gatwick Express from Victoria in 30 minutes, or Southern trains from Clapham Junction and London Bridge. East Croydon to Gatwick is 15 minutes by train.
Camden, Islington, and North London Good
Luton is the closest budget airport. Train from St Pancras takes around 25 minutes. King's Cross and St Pancras sit next to each other, with Piccadilly, Northern, Victoria, and Hammersmith lines all converging. The Piccadilly Line also runs to Heathrow from King's Cross in about 50 minutes.
Surrey and Outer Southeast Flexible
Gatwick is down the M23, around 20 to 30 minutes by car from most of Surrey. Southern rail connects East Croydon, Redhill, and the Gatwick corridor. Heathrow means crossing south London or looping the M25.
For most London-area travelers, LHR → AMS is the default.3 airlines, 367 flights/wk.
Explore LHR → AMS

Best pair by where you're staying in Amsterdam

Your Amsterdam airport matters as much as your London airport.
Canal Ring (Grachtengordel) Best
The semicircle of canals south of Centraal station. Walkable to everything, dense with restaurants, and the part of Amsterdam most first-timers picture. Hotels here are smaller and pricier per square foot than anywhere else in the city. The tradeoff is location for space.
De Pijp Good
South of the canal ring around Albert Cuyp Market. Better food scene than downtown, more neighborhood feel, and a 10-minute tram from Centraal. Works best for people who eat as a primary activity rather than an afterthought.
Jordaan Good
West of the main canals. Narrow streets, brown cafes, independent galleries. Quieter than Centrum after dark but a five-minute walk from everything. Slightly higher hotel prices for a noticeably calmer atmosphere.
Museumplein and Oud-West Tradeoff
Where the Rijksmuseum, Van Gogh Museum, and Stedelijk sit. Hotels here put you two minutes from the museum quarter and 20 minutes by tram from Centraal. Good base if art is the reason for the trip.
Zuidas
The business district south of the center. Corporate hotels, conference facilities, and a direct train from Schiphol that stops here before reaching Centraal. If your meetings are in Zuidas, skip the city center and cut your airport commute to under 10 minutes.
Noord Value
Across the IJ from Centraal, reachable by free ferry in five minutes. Former shipyards and warehouses turned into restaurants and studios. Cheaper hotels, but the neighborhood empties out after the last ferry at night.
AMS is the right Amsterdam airport for most travelers.Check individual route pages for ground transport from AMS.
Explore LHR → AMS

Which pair your airline flies nonstop

Loyalty programs drive airport choice for frequent flyers. Here's where each airline operates.
AirlineLHR–AMSLCY–AMSLTN–AMSSTN–AMS
British Airways
LATAM Chile
KLM
easyJet
Most airlines fly LHR → AMS.3 airlines serve multiple pairs.
Explore LHR → AMS

Ranked by on-time performance

On-time = departing within 15 min of schedule. Higher competition tends to keep airlines punctual.
LHR → AMS
Insufficient data — 367/wk doesn't generate meaningful OTP stats.
LCY → AMS
Insufficient data — 94/wk doesn't generate meaningful OTP stats.
LTN → AMS
Insufficient data — 33/wk doesn't generate meaningful OTP stats.
STN → AMS
Insufficient data — 11/wk doesn't generate meaningful OTP stats.
LGW → AMS
Insufficient data — 35/wk doesn't generate meaningful OTP stats.
SEN → AMS
Insufficient data — 5/wk doesn't generate meaningful OTP stats.
LHR → AMS has the most schedule depth.High competition keeps airlines punctual.
Explore LHR → AMS

Lounge access by airport and terminal

Premium lounge access varies dramatically by terminal. This alone can determine airport choice for some travelers.
LGW South Terminal No1 Lounge Good
Priority Pass and pay-per-entry. Decent food, bar, and seating. Gets crowded during holiday departures. The best lounge option in South Terminal if you do not have airline status.
LGW North Terminal Lounges Value
Smaller selection. A No1 Lounge and a couple of carrier-specific options. Quality is average. Gatwick does not have the lounge depth of Heathrow, which reflects its budget and leisure focus.
LHR T5 British Airways Galleries Top Tier
BA business class and oneworld Emerald or Sapphire. The Galleries First has a champagne bar and showers. The Club lounge is larger but more crowded. T5 is BA's home terminal and the lounge reflects it.
LHR T3 Virgin Clubhouse Good
Upper Class passengers on Virgin Atlantic Clubhouse or the BA Galleries for character. Shower access is available.
LHR Priority Pass / Amex Lounges Value
Plaza Premium and No1 Lounges accept Priority Pass and Amex Platinum across multiple terminals. Quality is hit or miss and they get crowded, especially during the morning departure wave. Better than nothing if your carrier does not have its own lounge.
STN Escape Lounge Value
Pay-per-entry and Priority Pass. Basic food, drinks, and seating. Stansted is a budget airport and the lounge options reflect that. Fine for a quiet hour before departure, but do not expect Heathrow-level quality.
LTN Aspire Lounge Value
Pay-per-entry and Priority Pass. Small, basic, and often crowded during peak travel periods. Luton is a budget airport and lounge expectations should match. Hot food, drinks, and a quiet corner if you get there early.
British Airways Lounge Top Tier
Open to Club Europe passengers and qualifying British Airways Executive Club members. Compact but clean, with food, drinks, and runway views. The terminal is small enough that you can leave the lounge 10 minutes before boarding and make your gate.
General Departures Area Good
If you do not have lounge access, the departures area has coffee shops and a few restaurants airside. The terminal is modern and the wait is rarely uncomfortable. Quick security processing means you do not need to arrive early.
No lounge facility
Southend does not have an airside lounge. The terminal past security has a small bar and cafe. If lounge access matters to you, this is not the airport for it.
KLM Crown Lounge (Non-Schengen) Top Tier
The main KLM lounge near the E gates. Spacious, with hot food, a full bar, and views of the tarmac. Access for business class on KLM or SkyTeam carriers, or Flying Blue Gold and above. Gets crowded during the evening rush of long-haul departures.
KLM Crown Lounge (Schengen) Good
Smaller and quieter than the non-Schengen version, near the B and C gates. Same access rules. Fine for a coffee before a short flight back to London.
Aspire Lounge Value
Pay-in lounge accessible with Priority Pass or a walk-in fee of around 40 euros. Locations on both sides of passport control. The food is basic but it beats sitting at the gate. Most non-KLM airlines direct their premium passengers here.
Your airline and cabin class determine which lounges you can access.Check route pages for terminal assignments.
Explore LHR → AMS

Ranked by flights per week

More flights = more flexibility. Miss your flight, catch the next one. Schedule depth is insurance.
LHR → AMS #1
367/wk (~52/day) — 3 airlines. A departure roughly every 27 minutes at peak.
LCY → AMS
94/wk (~13/day) — 2 airlines.
LTN → AMS
33/wk (~5/day) — 1 airlines.
STN → AMS
11/wk (~2/day) — 1 airlines.
LGW → AMS
35/wk (~5/day) — 1 airlines.
SEN → AMS
5/wk (~1/day) — 1 airlines.
LHR → AMS: 367 flights/week.Miss one flight, wait 27 min for the next.
Explore LHR → AMS

Getting to the airport

Cost and time vary by mode. Train is more predictable than driving.
Gatwick Express Best
30 minutes to Victoria station, nonstop. Runs every 15 minutes during the day. Victoria connects to the Victoria, District, and Circle lines. Fast and reliable.
Southern / Thameslink Trains Good
Cheaper than the Gatwick Express and run to more stations including London Bridge, Blackfriars, and St Pancras. Takes 30 to 45 minutes depending on route and stops. Good if your hotel is south of the river or near King's Cross.
National Express Coach Value
Budget bus to Victoria Coach Station. Takes 60 to 90 minutes depending on traffic. Very cheap but very slow. Only worth it if you are watching every pound.
Taxi Flexible
Expect around 70 to 120 pounds into central London. The drive is longer than from Heathrow and the M23/A23 can be slow. Not recommended unless you are headed to south London or have a lot of luggage.
Elizabeth Line Best
Contactless payment, 30 minutes to Paddington, and the line continues east through the West End to Liverpool Street and Canary Wharf without changing. Runs frequently from early morning. This is the default way into London for anyone not in a rush.
Heathrow Express Good
15 minutes nonstop to Paddington. Around 25 pounds. Faster than the Elizabeth Line but only saves you 15 minutes and costs significantly more. Worth it if your meeting starts in an hour.
Piccadilly Line Value
Cheapest option. 50 to 60 minutes into central London with stops at Hammersmith, Earl's Court, South Kensington, and King's Cross. Gets crowded during rush hour and there is no luggage space. Fine for budget travelers with a backpack.
Taxi / Minicab Flexible
Black cab from Heathrow to central London costs around 50 to 90 pounds depending on destination and traffic. Minicab apps are cheaper. The M4 motorway can be slow during morning rush. Takes 45 to 75 minutes.
Stansted Express Best
47 minutes to Liverpool Street station, nonstop. Runs every 15 to 30 minutes. Liverpool Street connects to the Central, Circle, Hammersmith, Metropolitan, and Elizabeth lines. The best option unless you are going north.
National Express Coach Value
Budget bus to Stratford, Liverpool Street, and Victoria. Takes 60 to 90 minutes depending on traffic and stops. Significantly cheaper than the train.
Taxi Flexible
Expect around 100 to 150 pounds into central London. The M11 can be slow. Only sensible if you are sharing the cost or heading to north London or Cambridge.
DART + Thameslink Best
The Luton DART connects the terminal to Luton Airport Parkway station in under 4 minutes. From there, Thameslink trains run to St Pancras, Farringdon, City Thameslink, and London Bridge. Total journey to St Pancras is around 35 to 45 minutes.
National Express / easyBus Value
Coach services to Victoria, Baker Street, and other London stops. Takes 60 to 90 minutes depending on traffic. Budget option.
Taxi Flexible
Expect around 80 to 130 pounds into central London. The M1 motorway can slow to a crawl near the city. Only practical if you are heading north of London or splitting the fare.
DLR (Docklands Light Railway) Best
London City Airport station is attached to the terminal. Trains run every few minutes to Bank station in about 20 minutes and to Canary Wharf in about 10. The cheapest and fastest way into the city.
Elizabeth Line from Custom House Good
Custom House station is about a 10-minute walk from the terminal. The Elizabeth line reaches Liverpool Street in about 12 minutes and Paddington in about 25. Useful if your destination sits along the Elizabeth line.
Taxi or Rideshare Flexible
A taxi to the City of London takes 15 to 25 minutes depending on traffic. To the West End, allow 30 to 40 minutes. The DLR is faster and cheaper for destinations along its line.
Greater Anglia train Best
Southend Airport station is attached to the terminal. Direct trains run to London Liverpool Street in around 55 minutes. Trains run every 15 to 20 minutes during the day.
Taxi or car Good
The airport is next to the A127 road. Taxis to Southend town center cost around 10 pounds. On-site parking is cheap compared to other London airports. If you live within driving distance, parking and driving is often the simplest option.
Weigh transit time against schedule flexibility.A faster airport with fewer flights may not save you time overall.
Explore LHR → AMS

Red-eye vs daytime departures

Departure timing affects jet lag, hotel costs, and how you spend your first day.
Not applicable
The flight is one hour. No carrier runs an overnight service between London and Amsterdam, and there would be no reason to.
LHR → AMS has the most departure options.Check the route page for schedule details.
Explore LHR → AMS

Premium cabin options

Business and first class products on this route, ranked by value and quality.
Eurostar Standard Premier Best
A meal, wider seat, and a quieter car for four hours from St Pancras to Amsterdam Centraal. No airport at either end, no security queue. On a route this short, the best premium experience is not in the air.
BA Club Europe Good
Short-haul business class from Heathrow Terminal 5. Middle seat stays empty, lounge access before boarding, and a meal service on a one-hour flight. The lounge time is worth more than the seat upgrade on a flight this short.
KLM World Business Class Flexible
KLM puts a 787 on this route when the connecting bank needs one, which means a lie-flat seat for a one-hour flight. Useful if you are connecting onward through Schiphol and the business class fare covers this leg as part of a longer itinerary.
Check route pages for cabin details per airline.Business class products vary significantly between carriers.
Explore LHR → AMS

Connecting through London from a domestic flight

Connecting through a third city adds hours to a one-hour flight. Four London airports fly Schiphol direct and the Eurostar covers the same corridor without leaving the ground. There is no connection routing that improves this trip.

Arriving LGW Best
Book LGW → AMS. Same airport, no ground transport needed. 1 airlines, 35/wk.
Arriving LHR Best
Book LHR → AMS. Same airport, no ground transport needed. 3 airlines, 367/wk.
Arriving STN Best
Book STN → AMS. Same airport, no ground transport needed. 1 airlines, 11/wk.
Arriving LTN Best
Book LTN → AMS. Same airport, no ground transport needed. 1 airlines, 33/wk.
Arriving LCY Best
Book LCY → AMS. Same airport, no ground transport needed. 2 airlines, 94/wk.
Arriving SEN
SEN has no Amsterdam nonstops. Your airline may offer a single-ticket connection through a hub. Otherwise, ground transport to a nonstop airport.
Self-connecting
Avoid cross-airport transfers. No direct transit links between most metro airports. Budget 4+ hours minimum if you must.
Check which London airport your domestic flight arrives at, then book Amsterdam from that same airport.LHR arrivals → LHR–AMS · LCY arrivals → LCY–AMS
LHR → AMS

London & Amsterdam Airport Profiles

Each airport has a personality. Terminal quality, transit access, lounge scene, and crowd levels vary dramatically — sometimes more than the flight itself.

LHR London Heathrow Airport Primary

Heathrow has four active terminals and your airline determines which one you use. Terminal 5 is British Airways territory, the newest and most polished. Terminal 2, the Queen's Terminal, handles Star Alliance carriers. Terminal 3 has Virgin Atlantic and several US carriers. Terminal 4 is smaller and serves a mix of international airlines.

The terminals are not walkable between each other. Free inter-terminal transfers run on the Elizabeth Line or Heathrow Express between T2/T3 (which share a central area) and T5. T4 requires a separate bus. Build in 60 minutes if you need to change terminals for a connection.

Immigration at 6 to 8 AM is slow. The morning wave of transatlantic red-eyes all land in the same window, and queues back up. E-gates work for US passport holders, which helps, but the volume is real. The airport is well-signed and functional, not beautiful. Shopping is extensive if you clear customs early.

Amsterdam Pairs
1
AMS
Airlines
3
Flights/Week
367
LCY London City Airport Secondary

London City Airport is the smallest of London's six airports, sitting in the Royal Docks between Canary Wharf and the Thames Barrier. The terminal is compact: one security area leads to a small departures lounge with views of the runway. You can arrive 30 minutes before a domestic flight and make it comfortably.

The runway is short, which limits the airport to smaller aircraft types. The approach is steep, which some passengers notice on landing. The upside of the small scale: no long walks to gates, no terminal train, no maze of corridors. A small selection of restaurants and shops sits airside.

Amsterdam Pairs
1
AMS
Airlines
2
Flights/Week
94
LGW London Gatwick Airport Secondary

Gatwick has two terminals, North and South, connected by a free shuttle train that takes about two minutes. South Terminal is the larger of the two and handles most scheduled long-haul flights. North Terminal serves a mix of short-haul and charter carriers.

The airport is smaller than Heathrow and easier to navigate. Security queues are generally shorter except during summer holiday peaks. The walk from security to gates in South Terminal is short. The overall experience is less stressful than Heathrow, which is part of the appeal for budget travelers.

Gatwick sits 30 miles south of central London, roughly twice the distance of Heathrow. The Gatwick Express runs to Victoria in 30 minutes, which is competitive, but Victoria is not as well connected to east London as Paddington.

Amsterdam Pairs
1
AMS
Airlines
1
Flights/Week
35
LTN London Luton Airport Secondary

Luton is a single-terminal airport 35 miles north of central London that has been undergoing expansion. The DART people-mover opened in 2023, replacing the old shuttle bus from the Luton Airport Parkway rail station. That shuttle bus was always the weakest link in getting to central London from Luton, and the DART fixes it.

The terminal is compact and functional. It serves mostly budget carriers on European routes. Any transatlantic service from New York is rare and seasonal. The airport handles fewer passengers than Heathrow, Gatwick, or Stansted, and it shows in the smaller food and retail options.

Luton works well for travelers headed to the north side of London, Bedfordshire, or the Midlands. For everyone else, the distance to central London and the limited flight options make it primarily a budget carrier airport.

Amsterdam Pairs
1
AMS
Airlines
1
Flights/Week
33
STN London Stansted Airport Secondary

Stansted is a single-terminal airport designed by Norman Foster, and the building itself is worth noticing. The roof structure is a clean white canopy held up by trees of steel columns. It opened in 1991 and still looks modern. The terminal is compact and navigation is straightforward.

Stansted is a budget carrier hub. Ryanair dominates the departure boards. Long-haul service is limited. Most traffic is European short-haul on budget carriers. The airport does one thing well: move large numbers of passengers through a simple layout with short walking distances.

It sits 40 miles northeast of central London, the farthest of the four London airports from the city. The Stansted Express runs to Liverpool Street in 47 minutes, which is reasonable, but you are starting from much farther out.

Amsterdam Pairs
1
AMS
Airlines
1
Flights/Week
11
SEN London Southend Airport Limited Service

London Southend is a small regional airport in Essex with a train station attached directly to the terminal building. The terminal handles a limited number of routes. Security queues rarely take more than 10 minutes, and the walk from the entrance to the gate is short.

The departures area past security has a few shops and food outlets. Do not expect the range of a larger airport. What Southend offers is speed: if you live nearby, you can leave home an hour before departure and make the flight.

Amsterdam Pairs
1
AMS
Airlines
1
Flights/Week
5
AMS Amsterdam Airport Schiphol Primary

Schiphol is a single-terminal airport, which sounds simple until you walk it. The building wraps around a central hall called Schiphol Plaza, with departure gates radiating outward in lettered piers. Some gates are a 20-minute walk from security. The upside of one terminal is that you never take a bus between buildings or guess which entrance to use. The downside is the distances once you are airside.

The airport sits on a former lake bed, below sea level. The train station is directly under the terminal. Walk out of arrivals, follow the signs down, and you are on a platform with service to Amsterdam Centraal and the rest of the Dutch rail network. Trains leave every few minutes. Schiphol compensates for long pier walks with clear signage and moving walkways, but leave time between connections.

London Pairs
6
LHR + LCY + LTN + STN + LGW + SEN
Nonstop from London
545/wk
Into Amsterdam
15 min
Train to Centraal

Full Comparison

Every airport combination ranked by schedule depth. LHR–AMS carries 67% of weekly flights with the best on-time record. LCY–AMS adds another 17%. The remaining 4 pairs share 15% between them.

RouteAirlinesFlights/WkShareDurationOTP
LHR → AMS 2 367
1h 20m Explore →
LCY → AMS 1 94
1h 05m Explore →
LTN → AMS 1 33
1h 10m Explore →
STN → AMS 1 11
1h 05m Explore →
LGW → AMS 1 35
1h 20m Explore →
SEN → AMS 1 5
1h 05m Explore →

Which Airlines Fly Which Pairs

British Airways and KLM serve both LHR and LCY to AMS — airport flexibility on the London side.

Not all planes are the same size. The aircraft type below each checkmark tells you whether you are getting a widebody (777, 787, A350) with wider seats and a quieter ride, or a narrowbody (737, A321) with a single aisle. On flights over five hours, the difference is significant.

LHR–AMS
LCY–AMS
LTN–AMS
STN–AMS
British Airways

A319, A320

E190
KLM

295, A321neo

E190
easyJet

A319, A320

A319, A320
LATAM Chile (codeshare)

A321neo

Route Facts

Total Nonstops
545/wk
Across 6 pairs
Airlines
4
3 on LHR–AMS
Fastest Pair
1h 20m
LHR → AMS
Distance
226 mi
364 km
London
6 airports
LGW, LHR, STN, LTN, LCY, SEN
Amsterdam
1 airports
AMS

Frequently Asked Questions

Common questions about London to Amsterdam flights.
From central London, yes. St Pancras to Amsterdam Centraal takes about four hours on the Eurostar. A flight is one hour in the air, but Heathrow is 15 miles from the city. Add the trip to the airport, check-in and security, boarding, the flight itself, deplaning, and a 15-minute train from Schiphol to Centraal, and the total is four to five hours. The Eurostar skips every airport step and drops you in the center of the city.
No, the Amsterdam to London Eurostar now runs direct. You used to have to get off in Brussels and clear UK border control before reboarding. That stop is gone. The return is the same trip as the outbound: about four hours, one seat, no transfer.
Heathrow. KLM and British Airways both fly to Schiphol with high frequency. Heathrow has the fastest transit links from most of London, and both carriers offer lounge access for premium passengers. Gatwick and Luton have easyJet service at lower fares, but the longer journey from central London eats into the savings.
Train, directly under the terminal, 15 minutes to Centraal. Walk out of arrivals, follow signs down to the platform, and trains run every few minutes. No reservation needed, no bus transfer, no shuttle between buildings. Schiphol to downtown Amsterdam is one of the shortest airport-to-city connections in Europe.
On a one-hour flight, the in-air product barely matters. Pick based on which schedule works and where you are connecting. KLM's hub is Schiphol, so if Amsterdam is not your final stop, KLM keeps your onward connection on one ticket. British Airways flies from Heathrow Terminal 5, which has better lounge options than KLM's Schengen-side facilities. If this is the whole trip, book whichever departure fits your day.
On the Eurostar, yes. An early departure from St Pancras gets you to Amsterdam Centraal by late morning, and return services run into the evening. That gives you six or seven hours in the city. Flying eats too much of the day in airport time on both ends to make a day trip worthwhile.