Convert Knots to Feet per Second (kn to ft/s)
1 knot (kn) = 1.687809857 feet per second (ft/s). 1 ft/s = 0.5924838013 kn. Example: 15 kn = 15 × 1.687809857 = 25.31714786 ft/s.
Also searched as knots to ft/s, knots in ft/s, knots into feet per second, kn to ft/s, kn in feet per second, kn into foot per second, knot to foot per second, kn to feet per second converter and how many feet per second in a knot.
1 kn = 1.687809857 ft/s
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk knot to foot per second converter to paste a column from Excel.
How to Convert Knot to Foot per Second
- 1 kn = 1.687809857 ft/s
- 1 ft/s = 0.5924838013 kn
- Example: convert 15 kn to ft/s: 15 kn = 15 × 1.687809857 ft/s = 25.31714786 ft/s
Formula
ft/s = kn × 1.687809857101
Derivation from SI units:
- 1 knot = 1 nautical mile (1852 m) per hour = 0.514444… m/s.
- 1 ft/s = 0.3048 m/s exactly.
- 1 kn = 0.5144444444444 m/s ÷ 0.3048 m/s per ft/s = 1.687809857101 ft/s
Both units are defined exactly, so the factor is exact. Knot definition: knot; Foot per Second definition: foot per second.
Worked examples
- A reading of 15 kn converts to 25.31714786 ft/s.
15 kn × 1.687809857 = 25.31714786 ft/s - A value of 50 kn is 84.39049286 ft/s.
50 kn × 1.687809857 = 84.39049286 ft/s
Knot to Foot per Second conversion table
| Knots (kn) | Feet per Second (ft/s) |
|---|---|
| 1 kn | 1.687809857 ft/s |
| 5 kn | 8.439049286 ft/s |
| 10 kn | 16.87809857 ft/s |
| 15 kn | 25.31714786 ft/s |
| 20 kn | 33.75619714 ft/s |
| 25 kn | 42.19524643 ft/s |
| 30 kn | 50.63429571 ft/s |
| 50 kn | 84.39049286 ft/s |
| 100 kn | 168.7809857 ft/s |
| 250 kn | 421.9524643 ft/s |
| 500 kn | 843.9049286 ft/s |
Where it's used
Knots are used for aviation and marine navigation, while feet per second appear in muzzle velocity and ballistics. Both measure speed (distance per time), so the conversion is a fixed factor.
Knot to other speed units
| Conversion | 1 kn equals |
|---|---|
| knot to foot per second | 1.687809857 ft/s |
| knot to meter per second | 0.5144444444 m/s |
| knot to kilometer per hour | 1.852 km/h |
| knot to mile per hour | 1.150779448 mph |
Frequently asked questions
How many feet per second are in 1 knot?
1 kn = 1.687809857 ft/s.
How do I convert knots to feet per second?
Multiply the value in kn by 1.687809857. For example, 15 kn × 1.687809857 = 25.31714786 ft/s.
Is the kn to ft/s conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4 (radian) and Table 8 (non-SI units accepted for use with the SI).
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "foot per second".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Knots to Feet per Second (kn to ft/s). Retrieved October 25, 2026, from https://scientificconverters.com/speed/knots-to-feet-per-second/
IEEE
Scientific Converters, "Convert Knots to Feet per Second (kn to ft/s)," scientificconverters.com. Accessed: Oct. 25, 2026. [Online]. Available: https://scientificconverters.com/speed/knots-to-feet-per-second/