Compare: London→Sydney (16,994 km) vs London→Tokyo (9,559 km). London → Tokyo wins by 7,435 km (44%). Side-by-side with flight & drive times.
By SnapDistance Team
16,994 km
10,560 miles · Flight: ~21h 45min
9,559 km
5,940 miles · Flight: ~12h 27min
✓ Shorter route
Difference: 7,435 km (44%) · Flight time difference: ~9h 18min
Verdict
London → Tokyo is the smarter pick if travel time and emissions matter most: it is 7,435 km (44%) shorter, saves about 9h 18min of flight time, and cuts roughly 1,895 kg of CO₂ per passenger. Choose London → Sydney only if the destination itself is the reason for the trip.
London → Tokyo is the shorter route at 9,559 km, which is 7,435 km (44%) shorter than London → Sydney. You would save approximately 9h 18min in flight time by choosing the shorter route.
| Metric | London → Sydney | London → Tokyo |
|---|---|---|
| Distance (km) | 16,994 | 9,559 |
| Distance (miles) | 10,560 | 5,940 |
| Flight time | ~21h 45min | ~12h 27min |
| Driving time | No road estimate | No road estimate |
| Road distance (rough estimate) | Not published | Not published |
| Continuous road link? | No | No |
| Cross-continental | Yes | Yes |
| Initial bearing | 61° (ENE) | 32° (NNE) |
| Time-zone shift | +10h | +8h |
| CO₂ – flight (per pax) | ~4,333 kg | ~2,438 kg |
| CO₂ – driving (per car) | — | — |
| Fuel cost (est.) | — | — |
Flying from London to Sydney produces roughly 4,333 kg of CO₂ per passenger, based on the ICAO/EEA short-haul emission factor of ~0.255 kg per passenger-km. The London → Tokyo flight emits about 2,438 kg. Choosing the shorter route saves approximately 1,895 kg of CO₂ per traveler — equivalent to 90 typical tree-years of carbon sequestration.
The London to Sydney route covers 16,994 km (10,560 miles), crossing from Europe to Oceania. London (population: 8,982,000) is located in England, United Kingdom, while Sydney (population: 5,312,163) is in New South Wales, Australia.
The London to Tokyo route covers 9,559 km (5,940 miles), spanning from Europe to Asia. London (population: 8,982,000) is in England, United Kingdom, and Tokyo (population: 13,960,000) is in Kanto, Japan.
Flying from London to Sydney takes approximately 21h 45min, while London to Tokyo takes 12h 27min.
Since both routes depart from London, this comparison is especially useful for travelers deciding between Sydney and Tokyo as a destination.
The 7,435 km difference between these routes is substantial and will significantly impact travel time and cost.
Neither route has a road figure we can defend. There is no continuous road connection between London and Sydney — the two cities sit on separate landmasses, so the journey requires air or sea transport. There is no continuous road connection between London and Tokyo — the two cities sit on separate landmasses, so the journey requires air or sea transport.
Sydney (Australia) has a population of 5,312,163 and is located in the New South Wales region of Oceania. As a major metropolis, it offers extensive international connections and diverse attractions.
Tokyo (Japan) has a population of 13,960,000 and is situated in Kanto, Asia. This major global city has multiple airports and world-class infrastructure.
Choose this route if your priority is reaching Sydney (Australia) — a city of 5,312,163 in the New South Wales region of Oceania. Despite being the longer of the two at 16,994 km, it makes sense when Sydney itself is the destination, the schedule fits better, or ticket prices are noticeably lower. This is a fly-only route in practice — overland travel is not realistic at 16,994 km. The initial bearing is 61° (ENE), so a great-circle flight leaves London heading roughly ENE.
This route is the right call if you are heading to Tokyo (Japan) — a city of 13,960,000 in the Kanto region of Asia. It is also the shorter of the two at 9,559 km, saving about 9h 18min of flying and around 1,895 kg of CO₂ per passenger. Overland travel is not practical for 9,559 km; flying is the realistic mode. Departing London, the great-circle bearing toward Tokyo is 32° (NNE).
London (51.51°, -0.13°) → Sydney (-33.87°, 151.21°): London keeps Europe/London time and Sydney keeps Australia/Sydney time — a gap of about 10 hours, with Sydney ahead. The exact gap moves when either zone switches to or from daylight saving, so use the live figure in the calculator for your travel dates. London (51.51°, -0.13°) → Tokyo (35.68°, 139.65°): London keeps Europe/London time and Tokyo keeps Asia/Tokyo time — a gap of about 8 hours, with Tokyo ahead. The exact gap moves when either zone switches to or from daylight saving, so use the live figure in the calculator for your travel dates. Both gaps come from the cities' real IANA zones and move with daylight saving. Shifts of 5 hours or more typically produce noticeable jet lag — plan one recovery day per three time zones crossed.
Tokyo is closer at 9,559 km, which is 7,435 km (44%) shorter.
16,994 km (10,560 miles). Flight: ~21h 45min.
9,559 km (5,940 miles). Flight: ~12h 27min.
Flying to Tokyo is faster at ~12h 27min, saving about 9h 18min compared to Sydney.
All distances on SnapDistance are calculated using the Haversine formula, which determines the great-circle distance between two points on Earth's surface. This gives the shortest possible distance over the globe, which is the measurement used for aviation and navigation. Actual travel distances by road or rail are typically 20-40% longer due to terrain, borders, and infrastructure routing. Flight times assume 800 km/h cruising speed with 30 minutes for takeoff and landing. Driving estimates use 80 km/h average speed with a 30% road distance factor.