How do I convert km/h to mph?

Multiply the speed in km/h by 0.621371 to convert to mph.

How do I convert mph to km/h?

Divide the speed in mph by 0.621371 to convert to km/h.

Does this tool save my data?

No. All calculations happen inside your browser.

Speed Converter (km/h ↔ mph)

Convert speed between kilometers per hour, miles per hour, and meters per second.

Speed in km/h

Speed in mph

How This Speed Converter Works

This tool converts speed between kilometers per hour (km/h), miles per hour (mph), and meters per second (m/s). These units are commonly used in driving, running, physics, and international travel.

Conversions use standard formulas:
km/h to mph: km × 0.621371
mph to km/h: mph ÷ 0.621371
km/h to m/s: km ÷ 3.6

All calculations happen instantly in your browser, ensuring privacy and fast performance.

Frequently Asked Questions

How many mph is 1 km/h?

1 km/h equals 0.621371 mph.

How many km/h is 1 mph?

1 mph equals 1.60934 km/h.

Does the tool store any data?

No. Everything is calculated locally on your device.