How fast is that, really?
Speeds span eleven orders of magnitude, so they only make sense on a logarithmic scale. Here is where your number falls.
96% of a cheetah
100 km/h is faster than 3 of the 11 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| garden snail | 0.0468 km/h | 2,137× | |
| walking human | 5.04 km/h | 19.8× | |
| Usain Bolt at full speed | 44.7 km/h | 2.24× | 44.72 km/h over 20 m in 2009 |
| cheetah | 104 km/h | 0.958× | |
| motorway traffic | 110 km/h | 0.908× | 110 km/h |
| bullet train | 300 km/h | 0.333× | 300 km/h in service |
| airliner at cruise | 900 km/h | 0.111× | |
| speed of sound | 1,235 km/h | 1/12.3 | Dry air at 20 °C |
| rifle bullet | 3,240 km/h | 1/32.4 | |
| International Space Station | 27,576 km/h | 1/276 | |
| speed of light | 1,079,252,849 km/h | 1/10,792,528 |
Worth knowing
- The gap between a snail and light is a factor of 23 billion. Everything humans do sits in the narrow band between walking and orbit.
- The fastest human-made object is the Parker Solar Probe at about 690 000 km/h — still only 0.064% of light speed.
Frequently asked
What is the fastest animal?
In level flight, the Brazilian free-tailed bat at about 160 km/h. In a dive, the peregrine falcon at nearly 390 km/h. On land, the cheetah at 104 km/h.
Why a logarithmic scale?
Because a linear one would put every terrestrial speed in the same pixel. Each step along this axis is a tenfold increase.