Speed Converter – km/h to mph and mph to km/h
Speed Converter
Convert velocity metrics instantly with high-precision decimals
Quick answer
A speed converter changes a speed between units. To convert km/h to mph, divide by 1.609344: 100 km/h = 62.14 mph. To convert mph to km/h, multiply by 1.609344: 60 mph = 96.56 km/h. The factor is exact because one mile is exactly 1.609344 km.
Our free speed converter switches between kilometers per hour and miles per hour in one click and shows the formula with your number. Use it for speed limits abroad, car and bike specs, running and cycling pace, weather wind speeds and physics homework.
km/h vs mph
Kilometers per hour (km/h) is used for road speeds in almost every country. Miles per hour (mph) is used in the United States, the United Kingdom and a few other places. Because a mile is longer than a kilometer, the same speed is always a bigger number in km/h than in mph. That is the first sense check for any speed converter result.
Speed Conversion Formulas
| Conversion | Formula | Example |
|---|---|---|
| km/h to mph | mph = km/h ÷ 1.609344 | 120 km/h = 74.56 mph |
| mph to km/h | km/h = mph × 1.609344 | 70 mph = 112.65 km/h |
| km/h to m/s | m/s = km/h ÷ 3.6 | 100 km/h = 27.78 m/s |
| mph to m/s | m/s = mph × 0.44704 | 60 mph = 26.82 m/s |
| km/h to knots | knots = km/h ÷ 1.852 | 100 km/h = 54 knots |
The tool on this page handles km/h and mph. For m/s and knots, use the formulas above.
How to Use the Speed Converter
Step 1: Choose km/h to mph or mph to km/h
Click km/h to mph or mph to km/h. The label and unit badge change to match. We keep km/h to mph selected.
Step 2: Enter the Speed
Type the speed into the speed converter input box. Decimals work. We enter 100 km/h, a common motorway limit.
Step 3: Click Convert Speed
Press Convert Speed. If the field is empty or negative, the speed converter asks for a valid value.
Step 4: Read the Converted Speed
The speed converter result shows 62.14 mph, rounded to two decimals, with the international standard (1 mph = 1.609344 km/h) and the formula with your number.
km/h to mph Chart
| km/h | mph |
|---|---|
| 20 | 12.43 |
| 30 | 18.64 |
| 40 | 24.85 |
| 50 | 31.07 |
| 60 | 37.28 |
| 80 | 49.71 |
| 90 | 55.92 |
| 100 | 62.14 |
| 110 | 68.35 |
| 120 | 74.56 |
| 130 | 80.78 |
| 150 | 93.21 |
| 200 | 124.27 |
| 300 | 186.41 |
mph to km/h Chart
| mph | km/h |
|---|---|
| 20 | 32.19 |
| 25 | 40.23 |
| 30 | 48.28 |
| 40 | 64.37 |
| 55 | 88.51 |
| 60 | 96.56 |
| 65 | 104.61 |
| 70 | 112.65 |
| 75 | 120.7 |
| 80 | 128.75 |
| 100 | 160.93 |
Quick Mental Shortcut
To estimate mph from km/h, multiply by 0.6: 100 km/h is about 60 mph (exact: 62.14). To estimate km/h from mph, multiply by 1.6: 70 mph is about 112 km/h (exact: 112.65). Close enough to read a road sign, but use the speed converter for anything official.
Common Speed Converter Mistakes
- Dividing when you should multiply. mph to km/h always gives a larger number.
- Using 1.6 for precise work. Over long distances or high speeds, the rounding adds up.
- Confusing knots with mph. A knot is 1.852 km/h, used at sea and in aviation.
- Mixing speed and pace. Runners often use minutes per km or per mile, which is time per distance, not distance per time.
For distances rather than speeds, use our mile to km converter.
Frequently Asked Questions
How do I convert km/h to mph?
Divide the km/h value by 1.609344. For example, 100 km/h ÷ 1.609344 = 62.14 mph.
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.
What is 120 km/h in mph?
120 km/h is 74.56 mph.
What is 70 mph in km/h?
70 mph is 112.65 km/h.
How do I convert km/h to m/s?
Divide by 3.6. For example, 72 km/h ÷ 3.6 = 20 m/s.
Is this speed converter free?
Yes. The VectraTools speed converter is free, needs no sign-up, and runs entirely in your browser.