Speed Converter (mph, km/h, m/s, knots)
Convert between the most common speed units instantly. Type a value in any field to see all the other units update automatically.
Quick presets:
Common conversions
| From | To | Multiply by |
|---|---|---|
| mph | km/h | 1.609344 |
| km/h | mph | 0.621371 |
| m/s | km/h | 3.6 |
| km/h | m/s | 0.277778 |
| knots | km/h | 1.852 |
| km/h | knots | 0.539957 |
How the speed converter works
We use meters per second (m/s) as an internal reference. Every time you type a value, we convert it to m/s, then from m/s to all the other units. This keeps all fields synchronized.
Base relations
- 1 km/h = 0.2777777778 m/s
- 1 mph = 1.609344 km/h
- 1 knot = 1.852 km/h
- 1 ft/s = 0.3048 m/s
FAQ
- Why do my numbers have many decimals? We keep precision to avoid rounding errors. Round to the number of decimals you need.
- Is speed the same as velocity? In physics, velocity has direction. This tool converts scalar speed.
Formula (LaTeX) + variables + units
This section shows the formulas used by the calculator engine, plus variable definitions and units.
Formula (extracted LaTeX)
\[','\\]
','\
Formula (extracted text)
Base relations 1 km/h = 0.2777777778 m/s 1 mph = 1.609344 km/h 1 knot = 1.852 km/h 1 ft/s = 0.3048 m/s
Variables and units
- No variables provided in audit spec.
Sources (authoritative):
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
- Initial audit spec draft generated from HTML extraction (review required).
- Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
- Confirm sources are authoritative and relevant to the calculator methodology.