Enter Speed to Convert
Converted Speed
Result: –
Scientific Form: –
Grouped Digits: –
Overview
Speed (or velocity) measures how far something travels per unit time. Common units include: m/s, km/h, mph, ft/s. In Advanced Mode, you can also convert between: knots (nautical miles/hour), Mach (speed of sound), ft/min, cm/s, mm/s, km/min, ft/hr, mi/min, mi/s, furlong/fortnight, in/hr, in/min, plus the constants speed of sound in air and speed of light in vacuum.
Knots: used in aviation and maritime.
Mach: ratio relative to the speed of sound (≈ 343 m/s at 20 °C, sea level). At higher altitudes (jet cruising ~11 km), speed of sound drops to ≈ 295 m/s.
Speed of sound in air: ≈ 343 m/s at sea level (20 °C), ≈ 295 m/s at altitudes around 11 km.
Speed of light in vacuum: exactly 299 792 458 m/s (used in physics).
Formula & Methodology
Internally, this converter uses meters per second (m/s) as the base unit. Conversions proceed in two steps:
- Convert the input value → m/s via the factor (unit → m/s).
- Convert m/s → target unit via the reciprocal factor.
Below is the table of “unit → m/s” factors used:
| Unit | Value in m/s | Notes / Definition |
|---|---|---|
| Meters per second (m/s) | 1 | 1 m/s |
| Kilometers per hour (km/h) | 0.2777777778 | 1000 m / 3600 s |
| Miles per hour (mph) | 0.44704 | 1 mph = 1609.344 m / 3600 s |
| Feet per second (ft/s) | 0.3048 | 1 ft = 0.3048 m |
| Knots | 0.5144444444 | 1 knot = 1 nautical mile/3600 s = 1852 m/3600 s |
| Mach | 343 | Speed of sound ≈ 343 m/s (20 °C, sea level) |
| Feet per minute (ft/min) | 0.00508 | 0.3048 m / 60 s |
| Centimeters per second (cm/s) | 0.01 | 1 cm = 0.01 m |
| Millimeters per second (mm/s) | 0.001 | 1 mm = 0.001 m |
| Kilometers per minute (km/min) | 16.6666666667 | 1000 m / 60 s |
| Feet per hour (ft/hr) | 0.0000846667 | 0.3048 m / 3600 s |
| Miles per minute (mi/min) | 26.8224 | 1609.344 m / 60 s |
| Miles per second (mi/s) | 1609.344 | 1609.344 m / 1 s |
| Furlong per fortnight (fur/fortnight) | 0.000166719 | 1 furlong = 201.168 m, 1 fortnight = 1 209 600 s |
| Inch per hour (in/hr) | 0.0000070556 | 0.0254 m / 3600 s |
| Inch per minute (in/min) | 0.0004233333 | 0.0254 m / 60 s |
| Speed of sound (air, 20 °C) | 343 | ≈ 343 m/s at sea level; varies with temperature and altitude |
| Speed of light (vacuum) | 299792458 | Exact constant 299 792 458 m/s |
Examples
-
Convert 10 m/s → km/h:
10 × (1 / 0.2777777778) = 36 km/h -
Convert 60 mph → m/s:
60 × 0.44704 = 26.8224 m/s -
Convert 100 knots → m/s:
100 × 0.5144444444 = 51.44444444 m/s -
Convert 5 Mach → km/h:
5 × 343 m/s = 1715 m/s → ×3.6 = 6174 km/h -
Convert 1000 ft/min → mph:
1000 × 0.00508 = 5.08 m/s → ÷0.44704 = 11.37 mph -
Convert 50 mi/s → km/h:
50 × 1609.344 = 80 467.2 m/s → ×3.6 = 289 681.92 km/h -
Convert 1 fur/fortnight → km/h:
1 × 0.000166719 = 0.000166719 m/s → ×3.6 = 0.00060019 km/h -
Convert speed of light → mph:
299 792 458 m/s → ÷0.44704 = 670 616 629 mph
Frequently Asked Questions
What is Mach 1 in km/h?
Mach 1 (343 m/s) ≈ 343 × 3.6 = 1234.8 km/h at 20 °C, sea level. At higher altitudes (e.g., 11 km), speed of sound drops to ≈ 295 m/s, so Mach 1 ≈ 1062 km/h.
How do I convert furlong per fortnight to m/s?
1 furlong = 201.168 m, and 1 fortnight = 14 days = 1 209 600 s, so 201.168 / 1 209 600 ≈ 0.000166719 m/s.
Why include speed of light?
The speed of light (299 792 458 m/s) is a fundamental physics constant. Including it lets you compare any speed to “c” directly.
What is knots used for?
Knots measure nautical miles per hour and are used in aviation and marine navigation. 1 knot = 0.514444 m/s.
Is this converter valid offline?
Yes. Once the page loads, all conversions occur in your browser. No additional internet access is needed.
Can I use this on my phone?
Yes. On smaller screens, the two columns collapse into one, and you can still toggle Advanced Mode to reveal or hide extra units.