Updated November 2026 · free, works in your browser
Formula and constants
Every value is converted to a base unit first (metres, or metres per second) and then to the target unit: result = value × factor(from) ÷ factor(to).
1 knot = 1,852 m per hour = 0.514444 m/s · 1 mph = 0.44704 m/s · 1 km/h = 0.277778 m/s · 1 nautical mile = 1,852 m · 1 statute mile = 1,609.344 m · 1 ft = 0.3048 m.
To convert knots to mph, multiply the number of knots by 1.15078. To convert nautical miles to kilometres, multiply by 1.852. The converter above does this instantly for speeds (knots, mph, km/h, m/s) and distances (nautical miles, statute miles, kilometres, metres, feet).
How to use the nautical unit converter
- Choose Speed or Distance with the two buttons at the top.
- Type your value, for example 10 for ten knots.
- Pick the unit you start with in "From" and the unit you want in "To". The swap button reverses them.
- Read the result straight away. The full version also lists the same value in every unit of that type and can copy a link to your result.
How it is calculated
Every value is first converted into a base unit, metres for distance and metres per second for speed, and then into the unit you chose:
result = value × factor(from) ÷ factor(to)
- 1 nautical mile = 1,852 metres exactly (the international definition).
- 1 knot = 1 nautical mile per hour = 1,852 m / 3,600 s ≈ 0.514444 m/s.
- 1 statute mile = 1,609.344 metres; 1 mph = 0.44704 m/s.
- 1 foot = 0.3048 metres exactly; 1 km/h = 1 / 3.6 m/s.
These are the standard international definitions used in navigation, aviation and metric conversion tables. Results are rounded for readability: two decimals for numbers of 100 or more, three decimals for numbers between 1 and 100, and four significant digits for smaller numbers.
Quick reference
| Knots | mph | km/h | m/s |
|---|---|---|---|
| 5 | 5.75 | 9.26 | 2.57 |
| 10 | 11.51 | 18.52 | 5.14 |
| 20 | 23.02 | 37.04 | 10.29 |
| 30 | 34.52 | 55.56 | 15.43 |
Frequently asked questions
Is a nautical mile the same as a normal mile?
No. A nautical mile is 1,852 metres, about 1.15 statute miles. It was originally tied to one minute of latitude, which is why it suits charts and navigation.
Is a knot a speed or a distance?
A knot is a speed: one nautical mile per hour. Saying "knots per hour" is therefore incorrect, since the hour is already part of the unit.
How do I convert knots to metres per second?
Multiply knots by 0.514444. For example, 20 knots is about 10.29 m/s. Select Speed, enter 20, and choose knots to m/s above.
Why do boats and aircraft use knots?
Because speed in knots maps directly onto charts: a vessel doing 6 knots covers 6 minutes of latitude in an hour, which makes distance, time and speed easy to work out.
How many feet are in a nautical mile?
One nautical mile is about 6,076.12 feet. Choose Distance, set nautical miles to feet and enter 1 to see it.
From the chart table to the coast
Knowing that a 12-knot passage is roughly 22 km/h makes it easier to judge how long a ferry, a charter leg or a coastal sail will take. That helps you plan arrival times and decide where to stay overnight. If your route ends in a harbour town or on an island, it is worth booking accommodation near the marina or the ferry terminal, so you are not racing the tide or the last departure.
This is only a unit converter. For actual navigation, always rely on up-to-date charts, instruments and official sources.
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