Speed conversion
Knots to Miles per hour (kn to mph)
Compare a marine wind or boat-speed reading in knots with miles per hour. A knot means a nautical mile per hour, not a land mile per hour.
1 kn ≈ 1.1508 mph — the calculator keeps the stored factor; this summary may be rounded.
A wind forecast stating 20 kn
- Starting measurement
- 20 kn
- Converted value (rounded if needed)
- 23.0156 mph
Keep knots on any record that requires them. This comparison uses the library’s stored, rounded knot factor and does not change the meaning of the forecast.
Knots to Miles per hour conversion chart
| knots | miles per hour |
|---|---|
| 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 |
| 30 kn | 34.5234 mph |
| 40 kn | 46.0311 mph |
| 50 kn | 57.5389 mph |
| 60 kn | 69.0467 mph |
| 80 kn | 92.0623 mph |
| 100 kn | 115.078 mph |
| 150 kn | 172.617 mph |
| 200 kn | 230.156 mph |
How to convert by hand
Reference relationship (display may be rounded)
1 kn = 1.15077845 mph
- Multiply the amount in knots by the number of miles per hour per unit.
- Use the calculator for the stored precision; copying a short displayed factor introduces extra rounding.
- Round the result to suit your measurement, after completing the calculation.
Related conversions
About knots and miles per hour
A converted speed describes the same motion in a different unit. Keep speed separate from pace, which is time per distance, and from travel time, which also needs a distance.
Knot
NauticalOne nautical mile per hour, or exactly 1.852 km/h. The calculator stores its metres-per-second factor in rounded form.
Commonly used for: Boat speeds, aircraft speeds and marine wind forecasts.
Mile per hour
US / ImperialA speed covering one land mile in one hour if maintained. Miles per hour use land miles, unlike knots.
Commonly used for: US and UK road speeds and speed comparisons in forecasts.
Questions
Is the knot factor stored exactly?
No. One knot is defined as one nautical mile per hour, but this calculator stores it as 0.514444 m/s. That rounded factor is retained in the calculation; showing more decimals cannot recover digits that were not stored.
Why might the chart and calculator show different decimal places?
The chart uses a compact rounded display. The editable calculator can show up to six decimal places and uses the factors or temperature formulas stored in the library. More displayed digits do not make the original measurement more precise.
Precision and source
The calculator uses stored conversion factors and temperature formulas, then rounds the result for display. A short decimal in a chart is not a claim of exactness. For a calculation with several steps, keep as much precision as the original measurement supports and round at the end.
The knot factor is stored as 0.514444 m/s. This is already rounded before the calculation, so this page does not promise an exact nautical conversion.
Reference: NIST SP 811 conversion factors. Its alphabetical tables distinguish unit variants and temperature readings from intervals. Published by ToolsNow. Report a conversion problem.
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