Speed Converter

Speed Converter Calculator

Convert speed in real time across 18+ units with one simple tool. Pick common units like km/h, m/s, mph, ft/s, and knots, or use advanced units like km/s and the speed of light. Enter your value once, and you’ll instantly see the answer in four other units—fast, clear, and accurate.

How to Convert Speed Units

Speed conversions use a conversion factor—a number that links one unit to another. Once you know the factor, converting speed is easy:

Start × Factor = Result

• Start (S): the value you have
• Factor (C): the conversion number
• Result (E): the value you want

What Is Speed?

Speed measures how fast something moves. It’s the distance traveled over a given time, and it doesn’t matter whether you’re moving forward, backward, or turning—speed stays positive.

A closely related term is velocity, which includes direction. That’s why velocity can be positive or negative, depending on which way you move.

Convert any unit to meters per second (m/s)

To change a speed into m/s, multiply by that unit’s factor.

Example (mph → m/s):

5 mph × 0.44704 = 2.2352 m/s

Convert from m/s to another unit.

To go from m/s into a different unit, divide by the same factor (or multiply by its reciprocal).

Example (m/s → mph):

2.2352 m/s ÷ 0.44704 = 5 mph

Convert between two non-m/s units (A → B)

You have two simple options:

Option 1 (two-step):

Convert A → m/s, then m/s → B.

Option 2 (one-step):

Use one direct factor: Factor(A) ÷ Factor(B)

Example (mph → km/h):

Direct factor = 0.44704 ÷ 0.2777778 ≈ 1.6093439

So: mph × 1.6093439 = km/h