How to Calculate Running Pace: Per Km, Per Mile and Finish Times

By HSP · Published October 20, 2026 · 6 min read · Health & Fitness

Ask two runners how fast they went and you will often get two different kinds of answer. One says "I ran 10 kilometres in an hour", the other says "I was doing about six-minute kilometres". The second answer is pace, and it is the number most runners, coaches and running apps actually use. Pace is easy to compare from one run to the next, it tells you whether you can hold a speed for a whole race, and it turns training plans into something you can follow on a watch. The maths takes less than a minute once you know the steps, and our free running pace calculator will check your answer instantly.

Pace versus speed

Speed and pace describe the same thing from opposite directions. Speed is distance per unit of time, such as 10 km per hour. Pace is time per unit of distance, such as 6 minutes per kilometre. A faster runner has a higher speed but a lower pace number, which confuses many beginners at first. To switch between them, divide 60 by one to get the other: a 6:00 per km pace is 60 ÷ 6 = 10 km/h, and 12 km/h is 60 ÷ 12 = a 5:00 per km pace.

The three-step method

1. Write your time in minutes. Turn hours into minutes (× 60) and seconds into a decimal (÷ 60). For example, 1 hour 4 minutes 30 seconds is 60 + 4 + 0.5 = 64.5 minutes.
2. Divide by the distance. Use kilometres for pace per km, or miles for pace per mile. The answer is minutes per unit, as a decimal.
3. Turn the decimal back into seconds. Multiply the part after the decimal point by 60. A result of 6.45 minutes is 6 minutes and 0.45 × 60 = 27 seconds, written 6:27.

That last step is where most mistakes happen. A pace of 5.5 is not "5 minutes 50 seconds"; it is 5 minutes 30 seconds, because half a minute is 30 seconds. If you would rather skip the conversion, a time calculator adds and splits hours, minutes and seconds for you.

Example 1: a 5K park run

You finish a 5 km run in 27 minutes 30 seconds.

• Time in minutes: 27 + 30 ÷ 60 = 27.5
• Pace: 27.5 ÷ 5 = 5.5 minutes per km, which is 5:30 per km
• Speed: 60 ÷ 5.5 ≈ 10.9 km/h

Type 5 km and 27:30 into the pace calculator and you will see the same 5:30 result, plus the per-mile figure.

Example 2: a run measured in miles

Your watch says 3 miles in exactly 30 minutes. The pace is 30 ÷ 3 = 10:00 per mile. To turn that into a per-km pace, divide by 1.609: 10 ÷ 1.609 ≈ 6.21 minutes, and 0.21 × 60 ≈ 13 seconds, so about 6:13 per km.

The rule is simple: one mile is 1.609344 km, so per-mile pace = per-km pace × 1.609, and per-km pace = per-mile pace ÷ 1.609. Our guide to converting miles to kilometres explains the conversion in more detail, and the unit converter handles any distance.

Predicting a finish time

Pace also works in reverse. Multiply your pace by a distance and you get the time it would take to run that far at the same pace. Standard road race distances are 5 km, 10 km, the half marathon (21.0975 km) and the marathon (42.195 km). At 6:00 per km, a half marathon takes 21.0975 × 6 = 126.6 minutes, or about 2:06:35.

Treat these as targets, not promises. Most people slow down over longer distances, so a pace you can hold for 5 km will usually feel much harder after 20 km. Hills, heat, wind and crowded starts also add time.

Working out the pace you need for a goal

If you have a goal time in mind, divide the goal by the distance. Want to break one hour for 10 km? 60 ÷ 10 = 6, so you need to average under 6:00 per km. For a 2-hour half marathon, 120 ÷ 21.0975 ≈ 5.69 minutes, and 0.69 × 60 ≈ 41 seconds, so the target is about 5:41 per km. Knowing this number before race day lets you check your watch at each kilometre marker instead of guessing.

Splits: checking your pace during a run

A split is the time for one section of a run, often each kilometre or mile. Even splits (every kilometre at roughly the same time) are usually the most comfortable way to run a steady effort. If your first kilometre is much faster than your target, you will probably pay for it later. You can time splits with a phone or the online stopwatch using its lap button, then compare each lap with your target pace.

Common mistakes

• Reading decimals as seconds. 6.3 minutes is 6:18, not 6:30.
• Mixing units. Dividing a time by miles gives pace per mile; do not label it per km.
• Using the wrong race distance. A half marathon is 21.0975 km (13.1 miles), not 21 km exactly; the extra 97.5 metres add about 35 seconds at a 6:00 pace.
• Trusting GPS blindly. Watches and phones can drift by a few percent, especially near tall buildings or under trees, so your measured distance may not match the course.

VSH take: pace is the most useful running number because it is honest and easy to compare. Write down the distance and time of your next few runs and work out the pace by hand once, so the numbers make sense, then let the calculator do it from then on. Most new runners improve fastest by running easy, at a pace where they can still talk, rather than chasing a faster number every day. If you are counting the energy you burn, our calorie calculator gives an estimate, and the daily water guide covers staying hydrated. This guide is general information, not medical or coaching advice; if you are new to exercise or have a health condition, check with a doctor before starting a running plan.