Speed Distance Time Calculator
Result
Average speed
- Speed in km/h
- 80.47 km/h
- Speed in m/s
- 22.35 m/s
- Pace per mile
- 1.20 minutes
- Pace per kilometer
- 0.75 minutes
A speed distance time calculator takes the two things you actually know about a journey — how far it was and how long it took — and gives you the average speed that implies, in miles per hour, kilometers per hour and meters per second. The division is plain: distance ÷ time. What makes it worth a page is that the two numbers rarely arrive in matching units, and that the answer people want is often not a speed at all. Runners and cyclists think in pace, which is the same information turned upside down — five minutes per kilometer rather than 12 km/h — and this page prints both, minutes per mile and minutes per km, next to the three speeds. Average speed is the other thing worth being clear about: it is the whole distance over the whole time, so a stop at traffic lights and a slow climb up a hill are already baked into it. That is the honest number for planning a journey, and it is the one this page computes.
Formula
average speed = distance ÷ time
- distance
- Distance covered, in miles
- time
- Elapsed time, in hours
- pace
- Minutes per mile, computed as 60 ÷ speed in miles per hour
Use it after a drive or a run to find out what you actually averaged, or before one to check whether a route is feasible in the time you have. It is also the honest way to compare two journeys: a motorway route that is longer in miles often wins on average speed, and only the arithmetic tells you by how much.
Worked examples
100 miles in 2 hours
- Distance: 100 miles
- Time: 2 hours
- Average speed: 100 ÷ 2 = 50 mph
- In metric: 50 × 1.609344 = 80.47 km/h
- In SI units: 50 × 0.44704 = 22.35 m/s
- Pace: 60 ÷ 50 = 1.20 minutes per mile, and 60 ÷ 80.47 = 0.75 minutes per km
50 mph is a round number and the other four are not, which is the point: only one of the five outputs can be a whole number, so the rest are where a wrong conversion factor would show up.
30 miles in 45 minutes
- Distance: 30 miles
- Time: 45 minutes, which is 0.75 hours
- Average speed: 30 ÷ 0.75 = 40 mph
- In metric: 40 × 1.609344 = 64.37 km/h
- In SI units: 40 × 0.44704 = 17.88 m/s
- Pace: 60 ÷ 40 = 1.50 minutes per mile, and 60 ÷ 64.37 = 0.93 minutes per km
The time goes in as hours even when you are thinking in minutes — 45 minutes is 0.75 of an hour. Switching the time unit in the form converts it for you, so there is no need to do that division by hand.
Limitations
Everything here is an average over the whole trip, so it says nothing about how fast you were going at any moment. A journey with a long motorway stretch and a slow crawl through a town can average the same as a steady country road, and the two feel nothing alike. The time you enter has to be the one you mean: elapsed time from door to door includes every stop, while a runner's moving time excludes them, and the two give different averages from the same distance. Nothing here accounts for acceleration, gradient or wind, and the pace figures assume a steady effort, which is why a hilly run will not hold one pace throughout. The speed of sound and the speed of light are not relevant to anything you would type here, and no output is checked against a legal limit — this page computes what happened, not what was allowed.
Frequently asked questions
- How do I work out average speed?
- Divide the distance by the time, both in matching units. 100 miles in 2 hours is 100 ÷ 2 = 50 miles per hour. If the time is in minutes, convert it to hours first — 45 minutes is 0.75 hours — and if the distance is metric, convert to miles, or switch the form's unit and let it do that for you.
- What is the difference between speed and pace?
- They are the same information measured in opposite directions. Speed is distance per unit of time, so a bigger number is faster; pace is time per unit of distance, so a smaller number is faster. Runners and cyclists use pace because it is what a watch shows at each mile or kilometer split, and because 5 minutes per km is easier to hold in your head than 12 km/h.
- Is this the same as the speed my car shows?
- No. A speedometer shows the speed at that instant; this page gives the average over the whole journey. On a motorway run with one stop for fuel, the two can be 10 miles per hour apart even though the car was sitting at the limit for most of the way. The average is the one that tells you how long the trip takes.
- Why are there three different speed units?
- Because three audiences read the same journey. Miles per hour is what a driver in the United States or Britain uses; kilometers per hour is what the rest of the world uses on the road; meters per second is what physics and engineering work in, and it is the coherent SI unit. All three come from the same division — 50 mph is 80.47 km/h is 22.35 m/s.
- How is a pace of 1.20 minutes per mile read?
- As 1 minute 12 seconds, not as 1.2 minutes in the decimal sense of the word — the 0.20 is a fifth of a minute, which is 12 seconds. That is why pace is usually quoted as minutes and seconds. This page prints it in decimal minutes because that keeps the arithmetic checkable, and converting 0.20 of a minute to 12 seconds is a multiplication by 60.
References
- NIST Guide to the SI, Special Publication 811 — US National Institute of Standards and Technology
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures