Speed Converter

Convert speed between metric and imperial units instantly.

Loading calculator…

About this calculator

Speedometers worldwide read km/h except US/UK (mph), while aviation and marine navigation stick to knots regardless of country. m/s is the SI scientific standard used in physics.

Formula

result = value × (from-unit factor ÷ to-unit factor), where factors are relative to the SI base unit.

Frequently Asked Questions

How exact are these conversions?

Factors use internationally agreed definitions — an inch is exactly 2.54 cm since 1959, a pound exactly 0.45359237 kg since 1959.

Why can't I enter zero or negatives?

Physical quantities here are magnitudes; negative lengths/weights are meaningless in this context.

📏

Length Converter

Convert length between metric and imperial units instantly.

⚖️

Weight Converter

Convert weight between metric and imperial units instantly.

🗺️

Area Converter

Convert area between metric and imperial units instantly.

🥤

Volume Converter

Convert volume between metric and imperial units instantly.

🌡️

Temperature Converter

Celsius ↔ Fahrenheit ↔ Kelvin with formula transparency.