Road signs use km/h or mph, sailors and pilots use knots, and physicists use metres per second. The converter also turns speed into running pace (minutes per kilometre and per mile) and into the Beaufort wind force number.
How to use the Speed Converter
- Pick the unit you are starting from in the From menu and type your value.
- Pick the unit you want in the To menu. The heading changes to match, for example “Kilometers per Hour to Miles per Hour Converter”.
- The most common speed units are shown below at the same time, so you can compare them at a glance.
- Type into any result to convert backwards, then use Copy results. The copied text starts with the heading for your chosen units.
Results update as you type. Everything is calculated in your browser.
How it works
Each of the 10 speed units on this page is defined by a factor relative to the metre per second, the base unit: 1 km/h = 0.27777778 m/s and 1 mph = 0.44704 m/s, for example. The calculator first turns the value you type into metres per second, then turns that into the unit you picked in the “To” menu and into metres per second, feet per second and knots. Typing into any result works backwards the same way, so the kilometres per hour and miles per hour values always describe the same amount.
How to convert speed units
- Choose the unit you have in the From menu and type the value, for example 100 km/h.
- Choose the unit you want in the To menu, for example miles per hour. The page heading changes to “Kilometers per Hour to Miles per Hour Converter”.
- The calculator multiplies by the metre per second factor of the “from” unit and divides by the factor of the “to” unit: 100 km/h × 0.27777778 ÷ 0.44704 = 62.137119 mph.
1 kilometre per hour in common units
| Unit | Value |
|---|---|
| Miles per hour (mph) | 0.62137119 |
| Metres per second (m/s) | 0.27777778 |
| Feet per second (ft/s) | 0.91134442 |
| Knots (kn) | 0.5399568 |
| Kilometres per second (km/s) | 0.00027777778 |
| Yards per second (yd/s) | 0.30378147 |
| Mach (Mach) | 0.00081629721 |
Kilometres per hour conversion table
| Kilometres per hour | mph | m/s | ft/s | kn |
|---|---|---|---|---|
| 1 | 0.62137119 | 0.27777778 | 0.91134442 | 0.5399568 |
| 5 | 3.106856 | 1.3888889 | 4.5567221 | 2.699784 |
| 10 | 6.2137119 | 2.7777778 | 9.1134442 | 5.399568 |
| 30 | 18.641136 | 8.3333333 | 27.340332 | 16.198704 |
| 50 | 31.06856 | 13.888889 | 45.567221 | 26.99784 |
| 60 | 37.282272 | 16.666667 | 54.680665 | 32.397408 |
| 80 | 49.709695 | 22.222222 | 72.907553 | 43.196544 |
| 100 | 62.137119 | 27.777778 | 91.134442 | 53.99568 |
| 120 | 74.564543 | 33.333333 | 109.36133 | 64.794816 |
Speed units explained
- Kilometre per hour (km/h)
- Kilometres per hour is the unit on road signs and speedometers in most countries. 100 km/h is about 62 mph.
- Mile per hour (mph)
- Miles per hour is used on roads in the U.S. and UK. 60 mph is about 96.6 km/h.
- Metre per second (m/s)
- Metres per second is the SI unit of speed, used in physics, wind measurement and athletics. Walking is about 1.4 m/s and Usain Bolt’s top speed about 12.4 m/s.
- Knot (kn)
- A knot is one nautical mile per hour, exactly 1.852 km/h. Ships, aircraft and marine weather forecasts use knots.
Common mistakes to avoid
Confusing knots with mph, and Mbps internet speeds (bits) with MB/s download speeds (bytes).
Good to know
The Beaufort number uses the WMO relation v = 0.836 × B^1.5 m/s, rounded to the nearest whole force and capped at 12 (hurricane force).
What each result means
- Pace per kilometre = 1000 ÷ [From] ÷ 60
- Pace per mile = 1609.344 ÷ [From] ÷ 60
- Beaufort wind force = min(12, round(([From] ÷ 0.836) ^ (2÷3)))
Formula
1 km/h = 0.62137119 mph
1 km/h = 0.27777778 m/s
1 km/h = 0.91134442 ft/s
1 km/h = 0.5399568 kn
1 km/h = 0.00027777778 km/s
Worked example
Inputs: From: 100 km/h.
Results: To = 62.13711922 mph; Metres per second = 27.77777778 m/s; Feet per second = 91.13444153 ft/s; Knots = 53.99568035 kn; Kilometres per second = 0.02777778 km/s; Yards per second = 30.37814718 yd/s; Mach = 0.08162972 Mach; Pace per kilometre = 0:36; Pace per mile = 0:58; Beaufort wind force = 10.
Frequently asked questions
How many km/h is 60 mph?
96.56 km/h.
What is a knot?
One nautical mile per hour, 1.852 km/h exactly.
What does Mach 1 mean?
The speed of sound; this converter uses 340.29 m/s, its value at sea level and 15 °C.
How many miles per hour are in one kilometre per hour?
1 km/h = 0.62137119 mph.
How many metres per second are in one kilometre per hour?
1 km/h = 0.27777778 m/s.
How many feet per second are in one kilometre per hour?
1 km/h = 0.91134442 ft/s.
Are these speed conversions exact?
All except Mach (Mach): it is based on a measured or agreed reference value, so treat the last digits as approximate. Every other factor is an exact definition.
Sources
Guides on this topic
- Running Pace Guide: Calculate, Convert and Predict Your Race Times: One 25-minute 5K, followed through every pace calculation runners use: per-mile and per-km conversion, splits, race prediction, training zones and treadmill speeds.