Knot to Foot per second Conversion Calculator: Free Online Tool
Convert knots to feet per second with our free online speed converter.
Knot to Foot per second Calculator
How to Use the Calculator:
- Enter the value you want to convert in the 'From' field (Knot).
- The converted value in Foot per second will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Speed category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Knot to Foot per second
Converting Knot to Foot per second involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Knot = 1.68781 feet per secondExample Calculation:
Convert 60 knots: 60 × 1.68781 = 101.2686 feet per second
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.
What is a Knot and a Foot per second?
The knot (kn) is a unit of speed equal to one nautical mile per hour, which is exactly 1.852 km/h (approximately 1.15078 mph or 0.514 m/s).
Feet per second (ft/s, fps, or ft/sec) is a unit of speed in the imperial and US customary systems. It measures the distance in feet traveled in one second.
Note: The Knot is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Foot per second belongs to the imperial/US customary system.
History of the Knot and Foot per second
The term knot originates from the 17th century practice of measuring ship speed using a "chip log". This device consisted of a rope with knots tied at uniform intervals (47 feet 3 inches or 14.4018 m), attached to a piece of wood shaped like a sector of a circle. The log was thrown overboard, and sailors counted the number of knots that passed through their hands in a specific time (usually measured by a 28-second sandglass). The number of knots counted in that time directly corresponded to the ship's speed in nautical miles per hour.
The foot as a unit of length has ancient origins, and the second became standardized more recently. Feet per second emerged as a logical unit for measuring speed in contexts where feet were the standard measure of distance, particularly before widespread metrication.
Common Uses for knots and feet per second
Explore the typical applications for both Knot (imperial/US) and Foot per second (imperial/US) to understand their common contexts.
Common Uses for knots
- Maritime Navigation: The primary unit for measuring vessel speed in maritime contexts worldwide.
- Aviation: Standard unit for indicating airspeed for aircraft globally.
- Meteorology: Commonly used to report wind speeds, especially in forecasts for marine and aviation purposes.
Common Uses for feet per second
- Physics & Engineering (Imperial/US): Used in calculations involving velocity and acceleration in systems using imperial units, particularly in older texts or specific industries (e.g., some aerospace applications).
- Ballistics: Often used to measure the muzzle velocity of firearms.
- Fluid Dynamics (Imperial/US): Can be used to express the speed of fluid flow in pipes or channels in US customary units.
- Some Scientific Instruments: Certain instruments might output readings in ft/s depending on their design and intended application region.
Frequently Asked Questions
Questions About Knot (kn)
What is a knot based on?
A knot is equal to one nautical mile per hour. A nautical mile is based on the Earth's circumference (one minute of latitude).
Is the knot an SI unit?
No, the knot is not an SI unit, but it is accepted for use with the SI, especially in navigation.
Why are knots used instead of mph or km/h in navigation?
Knots are convenient because one knot is one nautical mile per hour, and a nautical mile directly relates to the lines of latitude and longitude on navigational charts (one nautical mile is approximately one minute of latitude).
How do you convert knots to mph?
Multiply the speed in knots by approximately 1.151. So, 20 knots is about 23 mph.
How do you convert knots to km/h?
Multiply the speed in knots by 1.852. So, 20 knots is exactly 37.04 km/h.
About Foot per second (ft/s)
Is ft/s commonly used for everyday speed?
No, miles per hour (mph) is much more common for everyday speeds (like driving) in countries using the imperial/US customary system. ft/s is more technical.
Is ft/s an SI unit?
No, it belongs to the imperial and US customary systems. The SI unit for speed is meters per second (m/s).
How do you convert ft/s to mph?
Divide the speed in ft/s by 1.46667. So, 88 ft/s is approximately 60 mph.
How do you convert ft/s to m/s?
Multiply the speed in ft/s by 0.3048. So, 10 ft/s is equal to 3.048 m/s.
Conversion Table: Knot to Foot per second
| Knot (kn) | Foot per second (ft/s) |
|---|---|
| 1 | 1.688 |
| 5 | 8.439 |
| 10 | 16.878 |
| 25 | 42.195 |
| 50 | 84.391 |
| 100 | 168.781 |
| 500 | 843.905 |
| 1,000 | 1,687.81 |
All Speed Conversions
Conversion Formula
1 kn = 1.68781 ft/s
Where 1 Knot (kn) equals the calculated value in feet per second (ft/s).