How many ft/s are in 1 knots?

1 knots equals 1.687809857 ft/s, using the exact defined conversion factor rather than an estimate.

How do I convert knots to ft/s?

Multiply the knots value by 1.687809857. The converter above does this instantly to whatever precision you set.

How do I convert ft/s back to knots?

Use the reverse factor: 1 ft/s equals 0.5924838013 knots. You can also use the swap control in the converter above to flip the direction instantly.

ft/s (ft/s) is a unit of speed.

Is the knots to ft/s 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.

Knots to ft/s Converter

Q: 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).

About Converting Knots to ft/s

Knots and ft/s 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

ft/s = knots × 1.6878098571

This factor comes from each unit's defined relationship to the category's base unit: 1 knots equals 0.514444444444 base units, and 1 ft/s equals 0.3048 base units, so dividing one by the other gives the direct knots-to-ft/s factor of 1.6878098571.

Simple example

1 kn × 1.687809857 = 1.687809857 ft/s

1 knots = 1.687809857 ft/s.

Real-world example

10 kn × 1.687809857 = 16.87809857 ft/s

10 knots = 16.87809857 ft/s.

Conversion table

Knots (kn)	ft/s (ft/s)
1 kn	1.687809857 ft/s
5 kn	8.439049286 ft/s
10 kn	16.87809857 ft/s
25 kn	42.19524643 ft/s
50 kn	84.39049286 ft/s
100 kn	168.7809857 ft/s

Reverse conversion: ft/s to Knots

1.687809857 ft/s × 0.5924838013 = 0.9999999999 kn

1.687809857 ft/s = 0.9999999999 knots.

knots = ft/s × 0.592483801296

For a page dedicated to this direction, see ft/s 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 ft/s (ft/s)

Feet per second.

Knots — sources

BIPM SI Brochure — Non-SI units accepted for use with SI — Lists the knot among accepted non-SI speed units.

Knots to ft/s Converter — kn to ft/s

Speed Converter