Knots to Feet per Second Converter
Convert knots to feet per second — one knot is 1.688 ft/s. Results update as you type; exact factors shown.
One knot is 1.6878 feet per second — see the exact factor, not a rounded rule of thumb.
How the knots to feet per second converter works
Speeds convert through metres per second. 1 km/h is 1000/3600 m/s; 1 mph is 1609.344/3600 m/s; a knot is one nautical mile (1,852 m) per hour. Mach is shown against the standard sea-level speed of sound of 340.29 m/s and varies with altitude and temperature.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common speed conversions
| From | To | Units |
|---|---|---|
| 1 kn | 1.6878 ft/s | knot to feet per second |
| 5 kn | 8.439 ft/s | knots to feet per second |
| 10 kn | 16.8781 ft/s | knots to feet per second |
| 15 kn | 25.3171 ft/s | knots to feet per second |
| 20 kn | 33.7562 ft/s | knots to feet per second |
| 25 kn | 42.1952 ft/s | knots to feet per second |
| 30 kn | 50.6343 ft/s | knots to feet per second |
| 40 kn | 67.5124 ft/s | knots to feet per second |
| 50 kn | 84.3905 ft/s | knots to feet per second |
| 100 kn | 168.781 ft/s | knots to feet per second |
| 200 kn | 337.562 ft/s | knots to feet per second |
| 500 kn | 843.9049 ft/s | knots to feet per second |
Units in this converter and their exact factors
| Unit | Symbol | One unit in metre per seconds |
|---|---|---|
| metre per second | m/s | 1 metre per second |
| kilometre per hour | km/h | 0.2777777778 metre per second |
| mile per hour | mph | 0.44704 metre per second |
| knot | kn | 0.5144444444 metre per second |
| foot per second | ft/s | 0.3048 metre per second |
| Mach (sea level, 15 °C) | Ma | 340.29 metre per second |
FAQFrequently asked questions about speed conversion
How many ft/s is 1 knot?
1.688 ft/s.
What is a knot?
One nautical mile per hour — 1,852 m/h, which is one minute of latitude an hour.
What is 30 knots in ft/s?
50.6 ft/s.
Where is ft/s used?
US ballistics, wind loading and some aviation performance figures.
What is 1 knot in mph?
1.151 mph.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.