Knots to Feet Per Second
An instant knots-to-feet per second converter, with the formula and a reference table below.
| Knots | Feet Per Second |
|---|---|
| 1 kn | 1.68781 ft/s |
| 2 kn | 3.37562 ft/s |
| 3 kn | 5.06343 ft/s |
| 5 kn | 8.439049 ft/s |
| 10 kn | 16.878099 ft/s |
| 25 kn | 42.195246 ft/s |
| 50 kn | 84.390493 ft/s |
| 100 kn | 168.780986 ft/s |
How to use
- Enter a value in the Knots field.
- The Feet Per Second figure appears immediately — no button to press.
- Typing in the Feet Per Second field converts back to Knots the same way.
- Use the reference table for the values that come up most often.
Knots to Feet Per Second formula
To convert knots to feet per second, multiply by 1.68780986.
ft/s = kn × 1.68780986
Why this factor: the knot and the foot per second are both defined against the meter per second, so dividing one definition by the other gives 1.68780986 directly. Both definitions are set out in full below.
To go the other way, divide by 1.68780986 — or use the Feet Per Second to Knots converter, which is the same calculation reversed.
Worked example
Given 100 kn, multiplying by 1.68780986 yields 168.780986 ft/s.
100 kn × 1.68780986 = 168.780986 ft/s
The converter above does this for any value you type, in either direction.
What is a knot?
A knot is one nautical mile per hour, the speed unit of ships and aircraft.
Definition: Exactly 1,852 meters per 3,600 seconds, so about 0.514444 m/s.
Where it is used: Marine and aviation speeds, and wind speed in forecasts for sailors and pilots.
Worth knowing: Say 'knots', never 'knots per hour' — the 'per hour' is already inside the unit.
What is a foot per second?
Feet per second is a US engineering speed unit, common where distances are short.
Definition: Exactly 0.3048 meter per second, following from the exact definition of the foot.
Where it is used: Ballistics and muzzle velocities, fluid flow in pipes, and conveyor speeds in the US.
Knots vs Feet Per Second
The knot is a specialized unit while the foot per second is an imperial unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many feet per second are in a knot?
One knot equals 1.68780986 feet per second.
What is the formula to convert knots to feet per second?
Multiply the number of knots by 1.68780986. To reverse it, divide by 1.68780986 instead.
How do I convert feet per second back to knots?
Divide by 1.68780986, which is the same as multiplying by 0.592483801.
How many feet per second are in 10 knots?
10 kn works out to 16.878099 ft/s.
Is there anything to watch out for with knots?
Say 'knots', never 'knots per hour' — the 'per hour' is already inside the unit.
How is the knot defined?
Exactly 1,852 meters per 3,600 seconds, so about 0.514444 m/s.