Speed Converter

km/h, mph, m/s.

Inputs

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Formula

result = value × (from.toBase ÷ to.toBase)

km/h is the base. mph is stored as 1.60934 km/h and m/s as 3.6 km/h (since 1 m/s = 3.6 km/h). Same ratio method as length, applied to speed.

Worked example

100 km/h is about 62.14 mph — the speed you'd read on an Indian highway sign, converted for a US road trip or a car spec sheet quoted in miles per hour.

Where this can give the wrong answer

  • Wind speed and vehicle speed use the same units here; there's no separate 'knots' unit (1 knot ≈ 1.852 km/h).
  • Converting 0 km/h to any unit gives 0 — useful sanity check.
  • Mach number and speed of sound aren't included; m/s is the SI unit for physics problems.

FAQ

60 mph ≈ 96.56 km/h. The '100 km/h ≈ 60 mph' rule is a rough mental shortcut; this calculator uses the precise factor 1.60934.