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MPH to KM/H Converter

Understanding MPH and KM/H

Miles per hour (mph) and kilometers per hour (km/h) are units of speed measuring distance traveled per unit of time. The United States, United Kingdom, and a few other countries use mph for road signs and vehicle speedometers, while most of the world uses km/h. One mile equals exactly 1.609344 kilometers, so 1 mph = 1.609344 km/h.

How the Conversion Works

To convert mph to km/h, multiply by 1.609344. For example, 60 mph × 1.609344 = 96.56 km/h. For quick mental math, multiply by 1.6 and round. To convert km/h to mph, divide by 1.609344 (or multiply by 0.621371).

Frequently Asked Questions

How do I convert mph to km/h?

Multiply the mph value by 1.609344. For example, 60 mph × 1.609344 = 96.56 km/h. For quick mental math, multiply by 1.6.

What countries use mph?

Only the United States, United Kingdom, and Myanmar use miles per hour for road speed limits. All other countries use km/h.

Why do some countries use mph and others km/h?

The US, UK, and former British colonies originally used miles. Most of the world adopted the metric system starting in the 1790s.

What is a knot?

A knot is one nautical mile per hour, equal to 1.151 mph or 1.852 km/h. It's used in maritime and aviation worldwide.

How fast is 100 km/h in mph?

100 km/h equals 62.14 mph. This is a common highway speed limit in many countries.

What's the fastest speed limit in the world?

Germany's Autobahn has sections with no limit. Among posted limits, Texas has 85 mph (137 km/h) sections.