Unit Converters
Speed Converter
Speed: speed Converter converts between speed units — km/h, mph, m/s and knots — through a metre-per-second base. Worked through below with real figures, and the calculator repeats the working on your own inputs — free, on-device, instant.
Speed Converter takes your value plus the source and target units and gives back the converted speed in the unit you choose, applying fixed, standard conversion ratios. It's a quick, browser-based way to convert a speed measurement between units such as km/h, mph, m/s and knots.
A knot is one international nautical mile (1852 m) per hour; miles and feet use international definitions.
About this calculator
Speed is easiest to get wrong in the setup, not the arithmetic. Speed Converter converts between speed units — km/h, mph, m/s and knots — through a metre-per-second base. It matters whenever the same quantity is expressed in two systems and a wrong factor silently breaks the answer. The worked example on this page (Convert 100 km/h to mph: 100 ÷ 1.60934 = 62.14 mph (1 mile = 1.60934 km).) shows the full substitution; the calculator above runs the same working on your own numbers, in your browser, with nothing uploaded.
How to use
- Enter the speed value.
- Choose the From speed unit.
- Choose the To speed unit.
- Press Calculate to see the converted speed.
Why use Speed Converter
Fast
Calculations run in your browser. No round trip to a server.
Private
Your inputs never leave your device. Nothing is uploaded.
Free
No signup, no paywall, no ads-in-results, no watermarks.
Accurate
Uses standard conversion factors where applicable. Check critical engineering or measurement results before relying on them.
Mobile-ready
Optimised for phones, tablets, and desktops alike.
Transparent
Honest disclaimers wherever browser limits or regional rules apply.
Common uses
Use it for cross-checking a calculation
Speed in design and manufacturing
Use it for science and research
Use it for engineering and physics work
Use it for coursework and homework
Speed in trade and workshop work
Technical notes
Speed Converter converts between speed units — km/h, mph, m/s and knots — through a metre-per-second base.
Conversions use standard reference factors; for trade or engineering tolerances keep more decimal places than the display shows.
All arithmetic runs in your browser using double-precision floating point, so extreme inputs may show tiny rounding differences.
FAQ
Which speed units are supported?
Kilometres per hour, miles per hour, metres per second, knots, and feet per second.
How fast is 100 km/h in mph?
About 62.14 mph.
What is a knot?
One nautical mile per hour, about 0.514 metres per second.
Does the Speed Converter send my data to a server?
No. The Speed Converter runs entirely in your browser, so nothing you enter is uploaded, stored, or shared.
Worked example
Convert 100 km/h to mph: 100 ÷ 1.60934 = 62.14 mph (1 mile = 1.60934 km).