Speed Converter
Free online speed converter
Popular speed conversions
About speed units
Speed is distance over time. SI uses m/s; transport commonly uses km/h or mph; maritime/aviation use knots.
- Knot: 1 nautical mile per hour.
- Mach: ratio to local speed of sound.
Units in Speed Converter
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Kilometers per hour (km/h)
(kmh)
Kilometers per hour, used on road signs worldwide.
-
Knot (kn)
(knot)
Knot = 1 nautical mile per hour (1.852 km/h).
-
Mach (sea-level approx.)
(mach)
Mach = ratio to local speed of sound (Mach 1 ≈ 343 m/s at sea level).
-
Meters per second (m/s)
(ms)
Meters per second, SI unit of speed.
-
Miles per hour (mph)
(mph)
Miles per hour, used in US/UK road traffic.
Formulas and notes
1 knot = 1 nautical mile per hour (1,852 m/h). MPH ↔ km/h factor is 1.609344.
Quick examples
FAQ
Is speed conversion exact?
Many conversions are exact by definition (e.g., 1 in = 25.4 mm, 1 ft = 0.3048 m).
Can I share a specific result?
Yes. Every converter has a clean, shareable URL like
/convert/meter-to-foot/2.5.