How many feet per second is 1 knot?

1 knot equals approximately 1.6878 feet per second. The exact unit ratio is (1852 / 0.3048) / 3600 ≈ 1.6878098571.

A knot (symbol: kn or kt) is a unit of speed equal to one nautical mile per hour. One nautical mile is exactly 1852 meters — slightly longer than a statute mile (1609.344 m).

Why use feet per second instead of mph?

Feet per second (fps) is the standard unit in US ballistics, aerodynamics, and many engineering disciplines because it aligns with the foot-pound-second (FPS) system used in those fields.

How do I convert knots to fps manually?

Multiply the knot value by 1.68781. For example, 100 kn × 1.68781 = 168.78 fps. The factor comes from converting nautical miles to feet (6076.12 ft/nmi) then dividing by 3600 seconds per hour.

Is this converter accurate enough for engineering use?

Yes. The factor 1.6878098571 is accurate to 10 significant figures, well within the precision required for most aerospace and ballistics calculations.

Knots to Feet per Second Converter

Enter a speed in knots to instantly convert it to feet per second (fps) and other common units.

Speed Input

Quick presets

Factor: 1 kn = 1.68781 ft/s • 1 nautical mile = 6076.12 ft

Feet per Second

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ft/s

Miles per Hour

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mph

Kilometers per Hour

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km/h

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Summary

This knots-to-fps converter applies a factor of approximately 1.6878098571 to translate nautical knots into feet per second. One knot equals one nautical mile per hour; one nautical mile is 1852 meters, and one foot is 0.3048 meters, giving the precise underlying conversion ratio. Results also include mph and km/h for quick cross-reference.

How it works

Enter a speed value in knots (kn) in the input field.
The converter multiplies knots by 1.6878098571 to get feet per second.
mph is shown alongside by multiplying knots by 1.15077945.
km/h is shown by multiplying knots by 1.852 (exact by definition).
Use the Copy button next to any result to copy it to the clipboard.
Switch direction with the reverse toggle to convert fps back to knots.

Use cases

Calculate muzzle velocity in fps from ballistics data given in knots.
Convert aircraft airspeed from knots to fps for aerodynamic calculations.
Translate wind speed for structural engineering load calculations.
Cross-check missile or projectile speed figures across unit systems.
Academic physics problems requiring fps alongside nautical units.
Convert ship speed for hull resistance formulas that use fps.

Frequently Asked Questions

Last updated: 2026-06-15 · Reviewed by Nham Vu