A knot is one nautical mile per hour.
Knots to Kilometer per Seconds Converter — kn to km/s
Convert Knots (kn) to Kilometer per Seconds (km/s) using the exact conversion factor (1 knots = 0.0005144444 kilometer per seconds). See the formula, worked examples, conversion table, history, and common uses.
Knots to Kilometer per Seconds converter
Converter
Speed Converter
Convert road, aviation, marine, lab, and scientific speed units.
Context values
Some unit families need one extra value for a physically accurate result.
Distance divided by time.
Result = input x 0.5144444444 / 1000.
Speed uses meters per second as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Knots to Kilometer per Seconds
Knots and Kilometer per Seconds both describe speed, and the conversion matters whenever a maritime or aviation speed (knots) needs to be compared against a road speed (mph). Knots is most often used for ship and boat speed in marine navigation.
Formula
kilometer per seconds = knots × 0.000514444444444
This factor comes from each unit's defined relationship to the category's base unit: 1 knots equals 0.514444444444 base units, and 1 kilometer per seconds equals 1000 base units, so dividing one by the other gives the direct knots-to-kilometer per seconds factor of 0.000514444444444.
Simple example
1 kn × 0.0005144444444 = 0.0005144444 km/s
1 knots = 0.0005144444 kilometer per seconds.
Real-world example
10 kn × 0.0005144444444 = 0.0051444444 km/s
10 knots = 0.0051444444 kilometer per seconds.
Conversion table
| Knots (kn) | Kilometer per Seconds (km/s) |
|---|---|
| 1 kn | 0.0005144444 km/s |
| 5 kn | 0.0025722222 km/s |
| 10 kn | 0.0051444444 km/s |
| 25 kn | 0.0128611111 km/s |
| 50 kn | 0.0257222222 km/s |
| 100 kn | 0.0514444444 km/s |
Reverse conversion: Kilometer per Seconds to Knots
0.0005144444 km/s × 1943.844492 = 0.9999999136 kn
0.0005144444 kilometer per seconds = 0.9999999136 knots.
knots = kilometer per seconds × 1943.84449244
For a page dedicated to this direction, see Kilometer per Seconds to Knots.
Understanding the Knots
Knots (kn) measures speed. A knot is one nautical mile per hour; since the nautical mile is exactly 1,852 meters, a knot is exactly 1,852/3,600 m/s. It is classified as a Non-SI unit accepted for use with SI (maritime/aviation).
Where it's used: Used internationally in maritime navigation and aviation
Uses of the Knots today
- Ship and boat speed in marine navigation
- Aircraft airspeed and wind speed reporting in aviation
- Marine weather forecasts (wind speed)
History of the Knots
The knot gets its name from an old nautical method of measuring speed: sailors trailed a 'log line' with evenly spaced knots behind a ship and counted how many knots paid out over a fixed time, giving a direct speed reading in 'knots.'
The nautical mile it's based on was itself standardized internationally in 1929 (the International Nautical Mile, 1,852 m exactly), tying the knot to a precise value still used in shipping and aviation today.
Historical origin. Knots was not the invention of a single named person; it developed through the process described above.
Understanding the Kilometer per Seconds (km/s)
Distance divided by time.
Knots — sources
- BIPM SI Brochure — Non-SI units accepted for use with SI — Lists the knot among accepted non-SI speed units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many kilometer per seconds are in 1 knots?
1 knots equals 0.0005144444 kilometer per seconds, using the exact defined conversion factor rather than an estimate.
How do I convert knots to kilometer per seconds?
Multiply the knots value by 0.0005144444444. The converter above does this instantly to whatever precision you set.
How do I convert kilometer per seconds back to knots?
Use the reverse factor: 1 kilometer per seconds equals 1,943.844492 knots. You can also use the swap control in the converter above to flip the direction instantly.
What is a knots?
Knots (kn) measures speed. A knot is one nautical mile per hour; since the nautical mile is exactly 1,852 meters, a knot is exactly 1,852/3,600 m/s. It is classified as a Non-SI unit accepted for use with SI (maritime/aviation).
What is a kilometer per seconds?
Kilometer per Seconds (km/s) is a unit of speed.
Is the knots to kilometer per seconds conversion exact?
Yes. A knot is one nautical mile per hour; since the nautical mile is exactly 1,852 meters, a knot is exactly 1,852/3,600 m/s. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the knots still used today?
Used internationally in maritime navigation and aviation