Running Pace Calculator

Pace, time and distance

Pace is the time it takes to cover one unit of distance, written as minutes and seconds per kilometre or per mile. Runners use pace rather than speed because it maps directly onto a watch: if your pace is 5:00 per km, every kilometre should take five minutes. Pace, time and distance are linked by one simple relationship, so if you know any two you can work out the third:

pace = time ÷ distance  ·  time = pace × distance  ·  distance = time ÷ pace

Fill in two of the three boxes and leave the other one empty. If all three are filled, the calculator works out the pace from distance and time. Pick a race from the list to fill in its exact distance.

Worked examples

Notice the last two rows: a 2-hour half marathon and a 4-hour marathon need exactly the same pace, because the marathon is exactly twice as far. Running the full distance at that pace is, of course, much harder.

Converting between per km and per mile

One mile is 1.609344 km, so a pace per mile is 1.609344 times longer than the same pace per km. A 10:00 per mile pace equals 6:13 per km; 5:00 per km equals 8:03 per mile. Do not convert pace by simply multiplying the minutes, because the seconds part is in base 60: convert to total seconds first, multiply or divide, then turn it back into minutes and seconds.

Pace and speed

Treadmills and cycling computers show speed (km/h or mph) instead of pace. They are reciprocals: speed in km/h = 60 ÷ pace in minutes per km. A 5:00 /km pace is 60 ÷ 5 = 12 km/h; 10:00 per mile is 6 mph, or about 9.66 km/h. For more unit changes, see km/h to mph and km to miles.

Exact race distances

Official courses are measured along the shortest possible route, so GPS watches usually record a little more than the race distance because you weave around other runners and take wider lines on bends. If your watch says 42.6 km at the end of a marathon, the course was not long; you simply ran a slightly longer line. Aim for a pace a few seconds faster than your target to allow for it.

Using splits and negative splits

A split is the time for one segment of a run, usually each kilometre or mile. The calculator lists splits so you can check your progress during a race. Most coaches recommend even or slightly negative splits (the second half a little faster than the first). Starting too fast is the most common racing mistake: going out 15 seconds per km faster than your target in a 10K saves only a minute or two at best, but the extra lactate and fatigue often costs far more in the second half.

Choosing a training pace

• Easy runs should feel conversational, usually 60–90 seconds per km slower than your 5K race pace. Most of a beginner's weekly running should be at this effort.
• Tempo runs are "comfortably hard", roughly your one-hour race pace, held for 20–40 minutes.
• Intervals such as 400 m or 1 km repeats are run around 5K pace or faster, with recovery jogs between them.

Heart rate is a useful cross-check, especially in heat or on hills where pace naturally slows. The heart rate zone calculator gives target zones, and the calorie calculator helps you plan how much to eat on heavy training weeks.

Common mistakes

• Typing pace as a decimal. 5.30 minutes is 5 minutes 18 seconds, not 5:30. Use a colon: 5:30.
• Mixing units. A pace per mile with a distance in kilometres needs converting first; the calculator does this when you choose the units.
• Predicting a marathon from a 5K by pace alone. Endurance drops as distance increases, so you cannot hold your 5K pace for a marathon. Use the pace you actually ran in recent long runs and races of similar length.

Frequently asked questions

Sources

• World Athletics. Competition and Technical Rules, Book C2.1: road race course measurement.
• International System of Units (SI) and the international yard and pound agreement (1959): 1 mile = 1.609344 km.

Last reviewed 14 October 2026. Results are estimates; see our disclaimer.