Speed Converter
Convert a known speed between km/h, mph, m/s, ft/s, and knots. Built for dashboard checks, spec sheets, marine readings, and formulas that expect a different speed unit.
How It Works
Formula
Variables, symbols and units
- Input speed
- Converted speed
- Meters-per-second factor of the source unit(m/s)
- Meters-per-second factor of the target unit(m/s)
Calculation method explained
The calculator uses meters per second as the canonical base unit. Your entered speed is first converted into m/s, then converted again into the target unit. The result area also shows the same speed in the other supported speed units so you can cross-check a sign, tool, spec sheet, or formula without changing the target selector over and over.
Reference factors used by the calculator (meters per second per unit):
- 1 km/h = 0.2777777778 m/s
- 1 mph = 0.44704 m/s
- 1 m/s = 1 m/s
- 1 ft/s = 0.3048 m/s
- 1 knot = 0.5144444444 m/s
The value is first multiplied by the source factor to get meters per second, then divided by the target factor to land in the chosen unit.
Frequently Asked Questions
How does this speed converter work?
Each supported unit is defined as a fixed number of meters per second. The calculator multiplies your source speed into m/s first, then divides by the target unit factor. That keeps every pair on one auditable speed basis.
Why does the number get smaller when I convert to m/s or knots?
Because those units are larger than feet per second or kilometers per hour. The physical speed stays the same, but larger units need fewer counted units, so the numeric result drops.
What is a knot in this calculator?
One knot is one nautical mile per hour, which equals exactly 1.852 km/h or about 0.514444 m/s. That makes knots useful for marine and aviation-style speed references.
How is this different from speed-distance-time?
This tool only converts one known speed between units. The speed-distance-time calculator solves for an unknown speed, distance, or time from two related motion inputs.
Can I use this for running pace, legal limits, weather, or fuel economy?
No. This is only a speed-unit converter. It does not convert pace-style units, interpret speed limits, classify wind, or estimate efficiency.