Speed Converter

What is speed converter?

A speed converter changes how fast something moves between units. Cars use km/h or mph, science uses meters per second, and ships and aircraft use knots.

It helps when you read a speed limit abroad, compare vehicles, follow a weather report or solve physics problems.

How to use the speed converter

1. Enter the value.
2. Choose the unit you have and the unit you want.
3. Read the result and the table of all units.

How the speed converter works

Each speed is converted to meters per second using exact factors: one km/h is 0.27778 m/s, one mph is 0.44704 m/s and one knot is 0.51444 m/s. The result is divided by the target unit.

Worked example

Common uses of the speed converter

• Driving abroad.
• Physics and school work.
• Weather and wind reports.
• Sailing and aviation.
• Comparing vehicles.

Tips and common mistakes

To go from km/h to mph quickly, multiply by 0.62.

Use the table to compare many units at once.

Background: what to know before you rely on it

Speed units reflect their history. Kilometers per hour is the road unit across most of the world, miles per hour remains the legal unit in the United States and the United Kingdom, and the knot comes from sailors who measured speed by letting a knotted rope run out behind a ship. In science, meters per second is the standard because it fits the base units of the metric system. Wind speeds in weather reports may be given in any of these, so a converter prevents confusion.

Private, free and fast

This tool runs entirely in your browser. What you type or choose is not uploaded to a server and is not saved after you close the page, which keeps it fast and private. It is free to use as often as you like. See more in all converters, or browse the full list of tools.

Related tools

Results are for information and education. For legal, financial, medical or security decisions, check with a qualified professional. Check critical conversions with an official source.