How far away is space, really?
Space is 100 km straight up — closer than most people’s commute, and a distance a car could cover in an hour if roads went that way.
Almost exactly Kármán line
100 km is further than 6 of the 9 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| Burj Khalifa | 0.828 km | 121× | |
| skydiving altitude | 4 km | 25× | |
| Mount Everest | 8.85 km | 11.3× | |
| airliner cruise | 11 km | 9.09× | |
| Concorde cruise | 18 km | 5.56× | |
| weather balloon burst | 35 km | 2.86× | |
| Kármán line | 100 km | 1× | The usual boundary of space |
| International Space Station | 408 km | 0.245× | |
| GPS satellites | 20,200 km | 1/202 |
Worth knowing
- The Kármán line at 100 km is where you would have to fly faster than orbital speed for wings to generate lift — so you may as well be in orbit.
- The US Air Force uses 80 km as the boundary of space, which is why some astronaut wings are disputed.
Frequently asked
How high is space?
100 km by the Fédération Aéronautique Internationale definition, 80 km by the US one. Neither is a physical edge — the atmosphere just thins out.
Why does the ISS orbit at 408 km rather than 100?
Because at 100 km there is still enough air to drag it down within hours. At 408 km the ISS still loses about 2 km a month and needs regular reboosts.