How to Use the Speed Converter
Speed units vary by country and context. Miles per hour in the US, km/h almost everywhere else, knots in aviation and maritime. This converter handles them all.
Step-by-Step Instructions
- 1 Select the unit you are converting from.
- 2 Enter the speed value.
- 3 Select the unit you are converting to.
- 4 View the converted speed.
Understanding the Inputs
Value
The speed value you want to convert. Enter 60 to convert 60 mph to km/h (result: 96.56), 100 to convert 100 km/h to mph (result: 62.14), or 15 to convert 15 knots to m/s (result: 7.72).
How to find it: Read the speed from your source: a car speedometer (mph in US, km/h elsewhere), a running watch showing pace, an aircraft indicator (knots), a weather report, or a physics problem (m/s).
Why it matters: The speed value is the magnitude being converted. A small error like entering 65 instead of 60 mph changes the km/h result from 96.56 to 104.61 enough to matter for navigation or speeding fines.
Type: number · Default: 0
From
The speed unit your value is currently in. Choose from miles per hour (mph, used in USA and UK), kilometers per hour (km/h, used in most other countries), knots (nautical miles per hour, used in aviation and marine), or meters per second (m/s, scientific standard).
How to find it: Check the unit displayed on your source. US speed limit signs say mph. European car dashboards show km/h. Aircraft instruments show knots. Scientific papers use m/s.
Why it matters: The From unit defines what you are starting with. Converting 10 mph to km/h (16.09) is very different from converting 10 knots to km/h (18.52). Mistaking knots for mph could give a 15% error in navigation.
Type: select · Default:
To
The target speed unit you want the result in. If you are reading European road signs but your car speedometer is in mph, set To to mph to see how fast you should actually drive.
How to find it: This is determined by where the result will be used. Runners training overseas convert their usual pace. Pilots convert weather wind speeds. Scientists standardize to m/s.
Why it matters: The To unit gives the result meaning in your context. The same speed of 100 km/h equals 62.14 mph, 53.96 knots, or 27.78 m/s. Each is correct but only one is useful for your specific situation.
Type: select · Default:
Tips & Best Practices
- ✓ Speed limits in the US are in mph; most other countries use km/h.
- ✓ Knots are used in aviation and maritime. One knot equals one nautical mile per hour.
- ✓ Running pace is often expressed in minutes per mile or minutes per kilometer.
by CalculatorPro Tools · Updated 2026-07-29