Knots to MPH Converter
Convert knots to miles per hour instantly, with a reference table covering wind speeds, aircraft and vessels.
Knots to MPH Converter
1 kn = 1.1508 mph
Multiply knots by 1.15077945 to get miles per hour.
The link carries the values you entered, so whoever opens it sees the same result. Nothing is stored on our side — the numbers travel in the link itself.
Knots to miles per hour reference table
The conversions people look up most often, rounded to 4 decimal places.
| Knot (kn) | Mile per hour (mph) |
|---|---|
| 1 kn | 1.1508 mph |
| 5 kn | 5.7539 mph |
| 10 kn | 11.5078 mph |
| 15 kn | 17.2617 mph |
| 20 kn | 23.0156 mph |
| 25 kn | 28.7695 mph |
| 34 kn | 39.1265 mph |
| 40 kn | 46.0312 mph |
| 50 kn | 57.539 mph |
| 64 kn | 73.6499 mph |
| 100 kn | 115.0779 mph |
| 300 kn | 345.2338 mph |
| 500 kn | 575.3897 mph |
How the knots to mph converter calculation works
A knot is one nautical mile per hour, which makes it 1.15078 mph:
mph = knots × 1.15078
The unit is named for the method: sailors trailed a weighted log on a line knotted at fixed intervals and counted how many knots ran out in a timed interval. The intervals were spaced so the count gave speed directly.
It survives because a nautical mile is one minute of latitude, so speed in knots relates directly to position on a chart in a way mph never can.
Wind speed is where most people meet it. The hurricane categories are defined in knots and then converted, which is why their mph thresholds look arbitrary:
| Category | Knots | mph |
|---|---|---|
| Tropical storm | 34 | 39 |
| Category 1 | 64 | 74 |
| Category 3 | 96 | 111 |
| Category 5 | 137 | 157 |
The famous "74 mph" hurricane threshold is just 64 knots rounded.
Other cases:
- Sailing. 15 knots of wind is 17.3 mph — a good day. 25 knots is 28.8 mph and time to reef.
- Aviation. A cruise speed of 470 knots is 540.9 mph. Approach speeds around 140 knots are 161 mph.
- Shipping. A container ship at 20 knots does 23.0 mph, or 552 nautical miles a day.
For a rough figure, add 15%. And note that "knots per hour" is wrong — a knot already is a speed.
Frequently asked questions
How do I convert knots to miles per hour?
Multiply the number of knots by 1.15077945 to get miles per hour.
How many miles per hour are in 20 kn?
20 kn equals 23.0156 mph. The reference table on this page lists the other values people look up most often.
How do I convert miles per hour back to knots?
Divide the number of miles per hour by 1.15077945, or use the swap control on the converter above.
Is this conversion exact?
Yes. The factor is fixed by international definition rather than measured, so the conversion is exact - only the displayed rounding limits precision.
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