Knot Converter

What the Knot Converter does

Knot Converter: 1 kn = 1.852 km/h, so multiply a knot value by 1.852 to get kilometre per hour, or divide to go back. Example: 1 kn = 1.852 km/h.

The Knot Converter turns Value, From and To into Result, How it was calculated and Reverse conversion. Everything recomputes live, which makes it easy to test a few scenarios in a row.

Converting once from the original figure beats chaining approximations. The Knot Converter exists to take that particular chore off your hands.

Your data stays on your machine. Once the page has loaded you could disconnect entirely and it would still work.

Everything needed to verify a result is further down: the fields, the method and one fully worked example.

What do the Knot Converter fields mean?

The Knot Converter uses 3 inputs. It opens with a complete example loaded, which is usually the quickest way to understand what a field means.

How does the Knot Converter work?

Both units are converted through speed's base unit (m/s), so any of the 7 units in the dropdowns can be paired in either direction without loss of accuracy.

Where a unit has an exact legal definition, that exact value is used rather than a rounded one. The 1959 international agreement fixing the inch at 25.4 mm is the best-known example; the same principle applies throughout.

Worked example

These are the values the Knot Converter loads by default, and the result it produces from them. The numbers below come straight from the default inputs, so you can verify them against the live tool.

The knot

1 knot equals exactly 1 nautical mile per hour (0.5144444… m/s), and is the standard speed unit in both aviation and maritime navigation worldwide, including in fully metric countries, because it ties directly to the nautical mile’s basis in latitude.

Worth knowing

• The name comes from an old measurement method: sailors let out a rope with evenly spaced knots tied in it (a "chip log") over a fixed time, and counted how many knots passed overboard to estimate speed. The practice is centuries old, but the name stuck even after mechanical and electronic speed logs replaced it.
• Civil aviation reports airspeed in knots internationally by regulatory convention, regardless of whether the country otherwise uses metric or imperial units for everything else: a French airliner and an American one both report speed in knots to air traffic control.
• Because 1 knot equals 1 nautical mile per hour, and the nautical mile approximates one minute of latitude, a ship or aircraft travelling at a known number of knots can estimate distance travelled directly from elapsed time without needing a separate distance conversion.

Definitions: BIPM SI Brochure · NIST reference on units

How to use it

1. Key in Value.
2. Pick a value for From: the options are Metre per second (m/s), Kilometre per hour (km/h), Mile per hour (mph), Foot per second (ft/s), Knot (kn) or Mach (at sea level, 15 °C) (Mach).
3. Pick a value for To: the options are Metre per second (m/s), Kilometre per hour (km/h), Mile per hour (mph), Foot per second (ft/s), Knot (kn) or Mach (at sea level, 15 °C) (Mach).
4. There is nothing to click. The answer keeps pace with your edits.
5. Read Result, How it was calculated and Reverse conversion in the results panel.
6. To keep the result, either copy the link or print the page. Both preserve what is on screen.

What this tool does not do

• Conversion factors use SI definitions; some industries use their own rounded factors.
• Repeated conversions compound rounding, so convert once from the original value where possible.
• No allowance is made for local rules, regional variations or house conventions.
• A number that passes validation has been checked for plausibility, not for correctness.

Frequently asked questions

Related tools