MPH to km/h Converter
Quick answer: To convert MPH to km/h, multiply by 1.609344. For example, 10 mph is 16.09344 km/h. One mile per hour equals 1.609344 km/h.
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Use the MPH to km/h Converter
MPH to km/h formula and what each symbol means
km/h = mph × 1.609344
| Symbol | Meaning |
|---|---|
| mph | Mile per hour |
| km/h | Kilometer per hour |
MPH to km/h examples
1 mph
1 mph × 1.609344 = 1.609344 km/h.
10 mph
10 mph × 1.609344 = 16.09344 km/h.
100 mph
100 mph × 1.609344 = 160.9344 km/h.
MPH compared with km/h
One mph is 1.609 times as large as one km/h, so your number gets bigger when you convert MPH to km/h and smaller when you convert back. If the answer is not larger than what you typed, you divided instead of multiplying.
About MPH and km/h
Mile per hour (mph): Miles per hour, exactly 0.44704 m/s. Kilometer per hour (km/h): Kilometres per hour, used on road signs in most countries.
Where MPH to km/h conversions are used
Road signs use km/h or mph depending on the country, and aviation and shipping use knots. Sports results are quoted in m/s, km/h or mph.
How to calculate MPH to km/h step by step
- Enter the value in mph (the starting unit).
- Multiply by 1.609344, because 1 mph = 1.609344 km/h.
- The product is the value in km/h. To go back, divide by 1.609344 or multiply by 0.6213712.
Popular speed conversions
How to read your MPH to km/h result
Quick estimate: multiply by about 1.6 to get km/h from MPH; this is within 0.6% of the exact factor. To go from km/h to m/s divide by 3.6.
| MPH | KM/H |
|---|---|
| 1 | 1.609344 |
| 2 | 3.218688 |
| 5 | 8.04672 |
| 10 | 16.09344 |
| 20 | 32.18688 |
| 50 | 80.4672 |
| 100 | 160.9344 |
| 1,000 | 1,609.344 |
km/h to MPH: quick table
| KM/H | MPH |
|---|---|
| 1 | 0.6213712 |
| 5 | 3.106856 |
| 10 | 6.213712 |
| 25 | 15.53428 |
| 50 | 31.06856 |
| 100 | 62.13712 |
| 250 | 155.3428 |
| 500 | 310.6856 |
Common mistakes when calculating MPH to km/h
- Multiplying when you should divide: km/h to mph divides by 1.609344, while mph to km/h multiplies by it.
- Dividing when you should multiply: from mph to km/h multiply by 1.609344; from km/h to mph divide by 1.609344.
MPH to km/h FAQ
How many km/h are in 1 mph?
1 mph equals 1.609344 km/h.
How many mph are in 1 km/h?
1 km/h equals 0.6213712 mph.
Is 1 mph = 1.609344 km/h an exact conversion?
Yes. The mile per hour and the kilometer per hour are both defined exactly in SI terms, so the ratio has no measurement uncertainty; 1.609344 is just that ratio shown to 7 significant figures.
What is a kilometer per hour (km/h)?
Kilometres per hour, used on road signs in most countries.
How can I estimate MPH to km/h in my head?
Quick estimate: multiply by about 1.6 to get km/h from MPH; this is within 0.6% of the exact factor.
What is 7 mph in km/h?
7 mph = 11.26541 km/h (since 7 × 1.609344).
What is 40 mph in km/h?
40 mph = 64.37376 km/h (since 40 × 1.609344).
What is 200 mph in km/h?
200 mph = 321.8688 km/h (since 200 × 1.609344).
How many decimals should I keep when converting mph to km/h?
Match the precision of your original measurement. For example, 16.09344 km/h rounds to 16.1 km/h at 3 significant figures; keep more digits only for engineering or scientific work.
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Method, review and disclaimer
Edited by: Hemant Kumar and Anjita Rai, founders of ToolsVault (SEO and content professional, not a licensed adviser). Method: this tool runs in your browser using the formula shown on this page; the numbers you enter are not sent to our servers. Sources: NIST SP 811, Appendix B.8: conversion factors