How to convert miles per hour to knots
One mile per hour equals 0.868976 knots, so multiply the number of miles per hour by 0.868976:
kn = mph × 0.868976
mph = kn ÷ 0.868976 (1 kn = 1.1508 mph)
Example: 39 mph → 39 × 0.868976 = 33.8901 kn.
Going the other way, divide by 0.868976, or multiply by 1.1508; the knots to miles per hour converter does it for you.
Everyday values
| Miles per hour | Knots | For example |
|---|---|---|
| 39 mph | 33.8901 kn | gale force begins, roughly |
| 74 mph | 64.3042 kn | hurricane force begins |
| 100 mph | 86.8976 kn | 100 mph |
When you need this conversion
Divide mph by 1.151 to get knots. Pilots and sailors use knots because one nautical mile corresponds to one minute of latitude on charts.
Mile per hour to knot conversion table
| mph | kn | mph | kn |
|---|---|---|---|
| 10 mph | 8.6898 kn | 110 mph | 95.5874 kn |
| 20 mph | 17.3795 kn | 120 mph | 104.277 kn |
| 30 mph | 26.0693 kn | 130 mph | 112.967 kn |
| 40 mph | 34.759 kn | 140 mph | 121.657 kn |
| 50 mph | 43.4488 kn | 150 mph | 130.346 kn |
| 60 mph | 52.1386 kn | 160 mph | 139.036 kn |
| 70 mph | 60.8283 kn | 170 mph | 147.726 kn |
| 80 mph | 69.5181 kn | 180 mph | 156.416 kn |
| 90 mph | 78.2079 kn | 190 mph | 165.105 kn |
| 100 mph | 86.8976 kn | 200 mph | 173.795 kn |
About the units
- Mile per hour (mph): 1 mile per hour, exactly 1.609344 km/h.
- Knot (kn): 1 nautical mile per hour, exactly 1.852 km/h.
Both are units of speed. The conversion factor comes from the exact definitions above, so the calculator is exact; results are only rounded for display (up to six significant digits).
Frequently asked questions
How many knots are in one mile per hour?
One mile per hour is 0.868976 knots. One knot is 1.1508 miles per hour.
How do I convert miles per hour to knots?
Multiply the value in miles per hour by 0.868976. To go back, divide by 0.868976.
What is 39 mph in knots?
39 mph = 33.8901 kn.
What is 74 mph in knots?
74 mph = 64.3042 kn.
Sources
- NIST Special Publication 811 (2008), Guide for the Use of the International System of Units (SI), Appendix B: conversion factors.
- NIST Handbook 44 (2024), Appendix C: General tables of units of measurement.
Last reviewed 5 October 2026. Results are estimates; see our disclaimer.