Speed Calculator
Calculate speed from distance and time, and see it in metres per second, km/h, mph and knots.
Formula and sources updated · Data sources · 1View algorithm, constants and default inputs (JSON)
About this calculator
Speed is simply distance divided by time, but the unit you use changes the number dramatically. Converting to several units at once makes it easy to compare against any reference.
Worked example
calculated with the default values below
Distance 100 · Distance unit Metres · Time 9.58 · Time unit Seconds · To Metres per second Result 10.4384 · Metres per second 10.438 m/s · Kilometres per hour 37.578 km/h · Miles per hour 23.350 mph · Knots 20.291 kn · Pace per kilometre 1:36
Method and assumptions
Convert speed via metres per second, including international miles and nautical miles. Only the displayed unit definitions are converted; rounding and measurement uncertainty are separate.
Data sources
Disclaimer
These calculators give general conversion results. Rounding and the precision of the value you enter both affect the output, so treat displayed decimals as indicative rather than exact.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
v = d × k_d ÷ (t × k_t); km/h = 3.6v, mph = 2.23694v, kn = 1.94384v
- d
- Distance value
- t
- Time value
- k_d
- Distance→metres factor
- k_t
- Time→seconds factor
Factors: km 1000, mi 1609.344, yd 0.9144, ft 0.3048, nmi 1852; min 60, h 3600. Pace shown as min:sec per km.
Frequently asked questions
Why does the pace per kilometre differ from speed in kilometres per hour?
Speed and pace are inverses: the tool converts 100 metres in 9.58 seconds to 10.44 m/s, or 37.6 km/h, but pace reports minutes per kilometre, here about 1:36. That same 9.58-second hundred metres is essentially the 100 m world-record pace, yet pace per km looks very different from km/h because one divides distance by time and the other the reverse. Nautical miles and yards are offered so the same run can be compared across units.
Which inputs and limits apply to Speed Calculator?
Use the units shown beside each field. These are form limits, not recommended settings. Distance: 0–1,000,000,000,000; Time: 0.0001–1,000,000,000 Convert speed via metres per second, including international miles and nautical miles. Only the displayed unit definitions are converted; rounding and measurement uncertainty are separate.
What is a complete worked example for Distance = 100; Distance unit = Metres?
Inputs: Distance = 100; Distance unit = Metres; Time = 9.58; Time unit = Seconds; To = Metres per second. Calculation: v = d × k_d ÷ (t × k_t); km/h = 3.6v, mph = 2.23694v, kn = 1.94384v. Results: Result = 10.4384 m/s; Kilometres per hour = 37.578 km/h; Miles per hour = 23.350 mph; Knots = 20.291 kn; Pace per kilometre = 1:36 min/km.