Speed, Distance & Time Calculator

Solve for speed, distance or time — with unit conversions and pace.

Speed

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Assumes a constant average speed. Real journeys vary with traffic, terrain and stops.

The speed–distance–time triangle

These three quantities are locked together by one relationship, so knowing any two gives the third. Pick what you want to solve for and fill in the other two.

speed = distance ÷ time　·　distance = speed × time　·　time = distance ÷ speed

The only catch is keeping units consistent. The calculator converts everything internally — distance to metres, time to seconds — so you can mix kilometres with minutes or miles with hours and still get a sensible answer, including running pace in minutes per kilometre and per mile.

Worked example

Travelling 100 km in 1 hour 30 minutes is a speed of about 66.7 km/h (41.4 mph, 18.5 m/s). Turned around: at 66.7 km/h, covering 100 km takes 1 hour 30 minutes.

Everyday uses

This little triangle answers a lot of real questions: when will I arrive, what average speed do I need to make it on time, how far is that run, what pace hits my goal. Because it works in any direction, you can plan forwards or check backwards.

Good to remember

Use an average, not a maximum. Journey times depend on the speed you actually hold, including slow sections.
Pace and speed are inverses. A faster speed is a smaller minutes-per-kilometre pace.
Mind the units. Mixing miles with km/h by hand is a classic slip — let the conversions do it.

Frequently asked questions

What is the basic relationship?

Speed equals distance divided by time. Rearranged, distance is speed times time, and time is distance divided by speed. The calculator handles all three so you only enter the two you know.

Does this account for stops or changing speed?

No. It assumes a constant average speed. For a real journey with traffic, breaks and varying speed, use your expected average rather than a top speed.

What is pace and how does it differ from speed?

Pace is time per unit distance — minutes per kilometre or mile — which runners and cyclists often prefer. Speed is the inverse: distance per unit time. The calculator shows both.

Which units can I mix?

Any. Enter distance in km, miles or metres, time in hours, minutes or seconds, and read the answer in your preferred speed unit — the conversions are handled for you.