Speed Converter

ConversionEdited by Hemant Kumar and Anjita Rai, founders · How we checkUpdated Free · No sign-up

Quick answer: Choose a starting unit and a target unit, then enter a value. Common conversions: 1 km/h = 0.6213712 mph; 1 m/s = 3.6 km/h; 1 m/s = 2.236936 mph. This converter covers 7 speed units.

Use the Speed Converter

Speed formula and what each symbol means

target = value × (factor of starting unit ÷ factor of target unit), where each factor is the unit value in m/s.

Symbols used in the formula
SymbolMeaning
valueThe number you want to convert
factorThe unit’s size expressed in the base unit (m/s)

Speed examples

km/h to mph

10 km/h = 6.213712 mph.

m/s to km/h

10 m/s = 36 km/h.

m/s to mph

10 m/s = 22.36936 mph.

How to calculate Speed step by step

  1. Choose the starting unit and the target unit.
  2. Enter your value.
  3. Read the converted value, plus the conversion factor in both directions.

Popular speed conversions

How to read your Speed result

One mile per hour is exactly 0.44704 m/s, and one knot is exactly one nautical mile per hour, or 0.514444 m/s. To go from km/h to m/s divide by 3.6.

UNITSYMBOLEQUALSVALUE OF 1 M/S
Meter per secondm/s1 m/s = 1 m/s1 m/s
Kilometer per hourkm/h1 km/h = 0.27777778 m/s3.6 km/h
Mile per hourmph1 mph = 0.44704 m/s2.236936 mph
Knotkn1 kn = 0.51444444 m/s1.943844 kn
Foot per secondft/s1 ft/s = 0.3048 m/s3.28084 ft/s
Centimeter per secondcm/s1 cm/s = 0.01 m/s100 cm/s
Speed of lightc1 c = 299,792,460 m/s3.335641×10⁻⁹ c

Common mistakes when calculating Speed

  • Multiplying when you should divide: km/h to mph divides by 1.609344, while mph to km/h multiplies by it.
  • Mixing up knots and mph: a knot is about 15% faster than a mile per hour.
  • Forgetting to divide by 3.6 for km/h to m/s.

Speed FAQ

How many km/h is 1 mph?

1 mph is exactly 1.609344 km/h.

How many mph is 100 km/h?

100 km/h is about 62.14 mph.

What is a knot?

A knot is one nautical mile per hour, about 1.852 km/h.

What is the base unit for speed?

This converter uses meter per second (m/s) as the common base unit: every value is first converted to it and then to the target unit.

How do I convert between two speed units?

Choose the starting and target units, enter the value and read the result. By hand: convert to the base unit with the table, then divide by the target unit factor.

How many MPH are in 1 kilometer per hour?

1 km/h = 0.6213712 mph.

How many km/h are in 1 meter per second?

1 m/s = 3.6 km/h.

How many MPH are in 1 meter per second?

1 m/s = 2.236936 mph.

Which speed units does this converter support?

It covers 7 units: meter per second (m/s), kilometer per hour (km/h), mile per hour (mph), knot (kn), foot per second (ft/s), centimeter per second (cm/s), speed of light (c).

How accurate is the speed converter?

Results are calculated at full double precision and shown to about 8 significant figures. Round the answer to the precision of your original measurement; a result cannot be more accurate than the number you started with.

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Method, review and disclaimer

Edited by: Hemant Kumar and Anjita Rai, founders of ToolsVault (SEO and content professional, not a licensed adviser). Method: this tool runs in your browser using the formula shown on this page; the numbers you enter are not sent to our servers. Sources: NIST SP 811, Appendix B.8: conversion factors