Miles per hour to knots
Type a value in miles per hour to see it in knots straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the miles per hour box.
- Read the result in knots as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
kn = mph × 0.8689762419
Multiply the value in miles per hour by 0.8689762419 to get knots.
Example
To convert 25 mph to knots: 25 × 0.8689762419 = 21.7244 kn.
Conversion table
| Miles per hour (mph) | Knots (kn) |
|---|---|
| 1 | 0.868976 |
| 2 | 1.73795 |
| 3 | 2.60693 |
| 5 | 4.34488 |
| 10 | 8.68976 |
| 20 | 17.3795 |
| 25 | 21.7244 |
| 50 | 43.4488 |
| 100 | 86.8976 |
| 250 | 217.244 |
| 500 | 434.488 |
| 1,000 | 868.976 |
About the units
- Mile per hour
- Covering one international mile (1609.344 m) in one hour, exactly 0.44704 m/s. It is used on roads in the United States and the United Kingdom.
- Knot
- One nautical mile (1852 m) per hour, about 0.514444 m/s. It is the speed unit of aviation, shipping and wind reports.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many knots are in one mile per hour?
1 mph = 0.868976 kn exactly.
How do I convert miles per hour to knots?
Use kn = mph × 0.8689762419. For example, 25 mph = 21.7244 kn.
How many miles per hour are in one knot?
1 kn = 1.15078 mph.
How do I convert km/h to m/s in my head?
Divide by 3.6, because an hour is 3600 seconds and a kilometer is 1000 meters. For example 72 km/h is 20 m/s; multiply by 3.6 to go back.
Why do Mach values differ between sources?
The speed of sound depends on air temperature. We use 340.294 m/s at sea level and 15 °C; at 11 km altitude it is about 295 m/s, so Mach 1 is slower there.