Speed Converter
Miles per hour, kilometers per hour, knots and meters per second.
Speed Converter
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Units in this category
| Unit | Symbol | Exactly |
|---|---|---|
| kilometers per hour (km/h) | km/h | reference unit for this category |
| miles per hour (mph) | mph | 1.609344 km/h |
| meters per second (m/s) | m/s | 3.6 km/h |
| knots (kn) | kn | 1.852 km/h |
| feet per second (ft/s) | ft/s | 1.09728 km/h |
Where these factors come from
Speed units are exact distance definitions over exact time definitions: 1 mph = 1.609344 km/h exactly, and 1 knot = 1 nautical mile per hour = 1852 m/h exactly.
All 20 speed pairs
| from → to | km/h | mph | m/s | kn | ft/s |
|---|---|---|---|---|---|
| km/h (kilometers per hour) | — | 0.62137119 | 0.27777778 | 0.5399568 | 0.91134442 |
| mph (miles per hour) | 1.609344 | — | 0.44704 | 0.86897624 | 1.466667 |
| m/s (meters per second) | 3.6 | 2.236936 | — | 1.943844 | 3.28084 |
| kn (knot) | 1.852 | 1.150779 | 0.51444444 | — | 1.68781 |
| ft/s (feet per second) | 1.09728 | 0.68181818 | 0.3048 | 0.5924838 | — |
Conversions by starting unit
kilometers per hour (km/h)
km/h to mphkm/h to m/skm/h to knkm/h to ft/s
miles per hour (mph)
mph to km/hmph to m/smph to knmph to ft/s
meters per second (m/s)
m/s to km/hm/s to mphm/s to knm/s to ft/s
knots (kn)
kn to km/hkn to mphkn to m/skn to ft/s
feet per second (ft/s)
ft/s to km/hft/s to mphft/s to m/sft/s to kn
Common questions
Why do ships and planes use knots?
A knot is one nautical mile (1852 m) per hour, tied to latitude: one minute of arc on any meridian. It makes position plotting direct.
Is m/s bigger than km/h?
One m/s is 3.6 km/h. Physicists prefer m/s; road signs use km/h or mph.
How fast is 100 km/h in mph?
62.14 mph — the conversion factor is exactly 1.609344 km per mile.