How to convert kn to mph
mph = kn × 1.150779448. The scale factor is the source-unit factor divided by the destination-unit factor.
Worked example
For a constant or average travel speed of 20 kn converts to 23.01558896 mph.
- Start with 20 kn.
- Multiply 20 by 1.150779448.
- Report 23.01558896 mph, rounded to the precision of your original measurement.
Check the reverse conversion
1 mph = 0.8689762419 kn. Use the mile per hour to knot converter to calculate in the opposite direction. This has its own formula and reference table.
Definitions that matter
A knot is one international nautical mile per hour, not one mile per hour. Speed conversion does not calculate acceleration or journey time.
The base unit for this category is m/s. One kn corresponds to 0.5144444444 mps; one mph corresponds to 0.44704 mps. These definitions explain the relationship rather than relying on a rounded display value.
Sources and precision
Definitions: NIST Guide to the SI. Calculations use double precision; the tool defaults to a readable rounded result, while tables show up to ten significant digits. Displaying more digits does not increase the accuracy of the original measurement.
Read our calculation methodology and content standards, or continue with distance and time units across measurement systems.