Pace Calculator
Solve for any one of the three running variables: pace, time, or distance. Enter any two and the calculator finds the third, then shows your speed in four units, estimated finish times for standard race distances, and a per-kilometre split table.
Formula
Worked example
10 km in 50 minutes: pace = 50 / 10 = 5:00 min/km (8:03 min/mi). Speed = 10 / (50/60) = 12 km/h (7.46 mph). Marathon at this pace: 5.0 x 42.195 = 3h 31m 11s.
Three modes: pace, finish time, or distance
This calculator solves for any one of the three core running variables given the other two. In pace mode you provide a finish time and a distance, and the calculator returns your average pace in both min/km and min/mi, your speed in km/h and mph, and your finish time formatted for easy reading. In finish time mode you enter a target pace and a distance and the calculator tells you exactly how long that run will take. In distance mode you enter a time and a pace and the calculator tells you how far you will travel, useful for working out your long-run distance if you plan to run for 90 minutes at an easy pace. All three modes produce the same full set of output values so you always get pace, time, speed, and distance together.
Splits, race finish times, and speed zones
Turn on the per-km splits table to see your elapsed time at every kilometre mark assuming an even pace. This is useful for race planning when you want to check in at aid stations or hit a target halfway split. The reference table below shows estimated finish times for common race distances at your calculated pace, so you can see at a glance whether a 5K PB or a marathon goal is achievable at your current fitness. The speed gauge above the outputs shows where your pace falls on a scale from a walking pace up to elite running, classified by speed in km/h.
How pace and speed relate
Pace and speed are mathematical inverses. A pace of 5:00 min/km means you cover one kilometre every five minutes, which is the same as 12 km/h (7.46 mph). To convert pace to speed in km/h divide 60 by your pace in decimal minutes: 60 / 5.0 = 12 km/h. To convert the other way divide 60 by your speed: 60 / 12 = 5.0 min/km. Pace per mile is always longer than pace per km because a mile is 1.609 km, so you multiply pace per km by 1.609344 to get pace per mile. Most running watches and race clocks display pace per km in regions using the metric system and pace per mile in the USA and UK, so knowing both is useful for international comparisons.
Limitations and accuracy
All results here are mathematical averages over the full distance and do not account for splits, hills, wind, temperature, or fatigue. A GPS watch often over-measures distance by 0.5-2%, which shifts the calculated pace slightly. For race pacing purposes always use the official certified distance, not your GPS reading. This calculator assumes a constant pace; in reality most runners slow during the second half of a marathon. For more sophisticated race predictions that account for the physiological cost of longer distances, use the Riegel or VO2max-based race predictor formulas.
Estimated finish times by pace
| Race distance | 5:00 min/km | 6:00 min/km | 7:00 min/km | 8:00 min/km |
|---|---|---|---|---|
| 1 km | 5:00 | 6:00 | 7:00 | 8:00 |
| 5K | 25:00 | 30:00 | 35:00 | 40:00 |
| 10K | 50:00 | 1:00:00 | 1:10:00 | 1:20:00 |
| Half Marathon | 1:45:29 | 2:06:35 | 2:27:40 | 2:48:46 |
| Marathon | 3:30:58 | 4:13:10 | 4:55:22 | 5:37:33 |
At a steady even pace. Actual race times vary with course, conditions, and fatigue.
Frequently asked questions
What is a good running pace per kilometre?
A recreational runner typically averages 5:30 to 7:00 min/km. Competitive club runners often aim for 4:00 to 5:00 min/km, while elite marathon runners sustain under 3:00 min/km for the full 42.195 km. The right target depends on your fitness, the distance, and whether you are racing or doing an easy training run.
How do I calculate my finish time from a pace?
Multiply your pace in decimal minutes by the distance in km. A 5:30 min/km pace (5.5 minutes) over a half marathon (21.0975 km) gives 21.0975 x 5.5 = 116.0 minutes, or 1 hour 56 minutes. Switch to Finish Time mode in this calculator and it does the arithmetic for you in one step.
How do I convert pace per km to pace per mile?
Multiply your min/km pace by 1.60934. For example, 5:00 min/km x 1.60934 = 8:02.8 per mile, which rounds to 8:03 min/mi. This calculator always shows both automatically.
What is the difference between pace and speed?
Pace is the time taken to cover one unit of distance, for example 5:30 per km. Speed is the distance covered per unit of time, for example 10.9 km/h. They are mathematical inverses: speed (km/h) = 60 / pace (min/km). Runners generally prefer pace because it tells you directly how long each kilometre will feel during a race.
Why does the splits table assume an even pace?
The splits table uses your average calculated pace and applies it uniformly to every kilometre. Real runs involve warm-up, fatigue, hills, and tactical variation, so your actual split at kilometre 8 of a 10K will likely differ from your average. The table is a planning baseline, not a prediction of how every kilometre will feel.
How accurate is pace calculated from GPS distance?
GPS watches typically measure distance within 1-2% on an open road, but tree-lined routes, buildings, and wrist movement can introduce larger errors. For the most accurate average pace, use the official certified course distance (shown on race results) rather than your watch reading. An error of 1% in distance shifts your pace result by the same proportion.