This 5K pace calculator turns a finish time and a distance into minutes per kilometre and minutes per mile. The sample is 5 kilometres in 25:00. The headline is 5:00 per km. The same effort is 8:02.8 per mile, and the speed is 12 km/h, or 7.46 mph. The page then holds that pace still and applies it to a 10K, a half marathon of 21.0975 kilometres, and a marathon of 42.195 kilometres. At the sample pace those clocks are 50:00, 1:45:29.3, and 3:30:58.5.
The distance does not have to be a 5K. Choose kilometres or miles and type the distance you actually covered. A mile in 8:00 is 4:58.3 per kilometre and projects a 5K of 24:51.3. The form does not estimate calories, and it does not know whether you can hold the pace for a longer race. The maintenance-calorie page uses body size and an activity multiplier. A 25:00 5K does not replace that multiplier, and 2,633 calories is not a pace. Use one page for the clock and the other for the daily energy estimate.
How to use this calculator
- Enter the distance as a number. The sample, 5, is a 5K when the unit is kilometres.
- Choose kilometres or miles. A mile on this page is the international mile, 1.609344 kilometres, not a casual 1.6.
- Enter the finish time as hours, minutes, and seconds. The sample is 0 hours, 25 minutes, and 0 seconds. You can type 90 in the minutes field instead of 1 hour and 30 minutes. The fields are added together.
- Press Calculate. If the unit is kilometres, the headline is the pace per kilometre. If the unit is miles, the headline is the pace per mile. The other pace, the speed, and the race projections are underneath.
How a finish time becomes a pace
The time fields become one number of seconds: hours times 3,600, plus minutes times 60, plus seconds. The distance becomes kilometres. A mile entry is multiplied by 1.609344. Pace per kilometre is the seconds divided by the kilometres. Pace per mile is the seconds divided by the miles, which is the same as multiplying the per-kilometre pace by 1.609344. For the sample, 1,500 seconds divided by 5 kilometres is 300 seconds, which is 5:00. Multiply 300 by 1.609344 and the per-mile pace is 482.8032 seconds, which rounds to 8:02.8 on the display. Speed in kilometres per hour is the distance in kilometres times 3,600, divided by the seconds. Five kilometres in 1,500 seconds is exactly 12 km/h.
The race lines do not look up a course. They multiply the per-kilometre pace by a fixed distance. A 10K is 10 kilometres, so the sample doubles to 50:00. A half marathon is 21.0975 kilometres, which is 6,329.25 seconds at this pace and displays as 1:45:29.3. A marathon is 42.195 kilometres, which is 12,658.5 seconds and displays as 3:30:58.5. The clock rounds to the nearest tenth of a second. A time that lands on a whole second, such as 25:00 or 50:00, does not show a decimal.
A common road marking of 13.1 miles is not the half-marathon line. 13.1 times 1.609344 is about 21.082 kilometres, a little short of 21.0975. Type 13.1 miles and 1:45:00 and the headline is 8:00.9 per mile, while the half-marathon projection is 1:45:04.5. The four and a half seconds are the gap between 13.1 miles and the standard half-marathon distance, not a rounding glitch in the 1:45:00 you typed. A 5K is exactly 5 kilometres on this page. It is not 3.1 miles. Three miles is 4.828032 kilometres, about 172 metres short of a 5K.
Nothing in the formula uses weight, age, heart rate, or hills. Two runners with the same average pace took the same time to cover the distance, whatever it felt like. The projection assumes the average pace continues. Most runners do not run a marathon at their 5K pace. The lines are a scale, so you can see how demanding that assumption is, not a prediction that the scale will happen. The calorie calculator cannot see this pace either. Its sample man, 30 years old, 75 kg, 175 cm, and a 1.55 multiplier, stays at 2,633 calories/day whether the 5K was 25:00 or 30:00.
Formula
Total seconds = hours × 3,600 + minutes × 60 + seconds Kilometres = distance, or distance × 1.609344 when the unit is miles Miles = kilometres ÷ 1.609344 Pace per kilometre = total seconds ÷ kilometres Pace per mile = total seconds ÷ miles Speed (km/h) = kilometres × 3,600 ÷ total seconds Speed (mph) = miles × 3,600 ÷ total seconds 10K time = pace per kilometre × 10 Half marathon time = pace per kilometre × 21.0975 Marathon time = pace per kilometre × 42.195 Displayed clocks round to the nearest tenth of a second
A 30:00 5K is 6:00 per kilometre and 9:39.4 per mile. Speed is 10 km/h, or 6.21 mph. The 10K line is 1:00:00. The half marathon is 2:06:35.1. The marathon is 4:13:10.2. Each of those is the 25:00 sample scaled by 30/25, then rounded to a tenth of a second on its own clock. The per-mile figure is not 6:00 times 1.6. Using 1.6 instead of 1.609344 would show 9:36.0 per mile and would be 3.4 seconds fast.
An 8:00 mile is 480 seconds. Divided by 1.609344, the per-kilometre pace is 298.256 seconds, which displays as 4:58.3. Five kilometres at that pace is 1,491.3 seconds, or 24:51.3. The speed is 12.07 km/h and 7.50 mph. The sample 5:00-per-kilometre pace is slower than an 8:00 mile, even though 5:00 times 1.6 looks like 8:00 if the mile is shortened. The international mile is why the sample prints 8:02.8 rather than 8:00.
Worked pace examples
A 25:00 5K
Distance 5, unit kilometres, time 0:25:00. The headline is 5:00 per km. Pace per mile is 8:02.8. Speed is 12 km/h (7.46 mph). The 5K line repeats 25:00 because that is the distance you typed. The 10K line is 50:00. The half marathon is 1:45:29.3. The marathon is 3:30:58.5. Those last two use 21.0975 km and 42.195 km, not “about 13 miles” and “about 26 miles.”
The same pace typed as 10 kilometres in 50:00 produces the same headline and the same race lines. The time-entered line changes to 50:00 for 10 kilometres. The calculator is dividing, not remembering that the field was labelled 5K. A 5K that took 50:00 would be 10:00 per kilometre. Do not leave the distance at 5 if the time you are typing is a 10K.
A 30:00 5K, and an 8:00 mile
Change only the minutes, from 25 to 30. The headline is 6:00 per km. Pace per mile is 9:39.4. Speed is 10 km/h (6.21 mph). The half marathon projection is 2:06:35.1 and the marathon projection is 4:13:10.2. The 5:00 pace was 12 km/h. This one is 10 km/h. The ratio of the times is 30/25 = 1.2, and 12 ÷ 1.2 is 10. The per-mile clock is not 1.2 times 8:02.8 in a way you should do by hand if you want the rounded display. Use the result line.
Switch the unit to miles, set the distance to 1, and set the time to 8:00. The headline is 8:00 per mile. Pace per kilometre is 4:58.3. A 5K at that pace is 24:51.3, a 10K is 49:42.6, a half marathon is 1:44:52.5, and a marathon is 3:29:45. The marathon lands on a whole second after rounding, so it has no decimal. This 8:00 mile is quicker than the 25:00 5K, which needed 8:02.8 per mile.
13.1 miles in 1:45:00 is not quite a half marathon
Distance 13.1, unit miles, time 1 hour, 45 minutes, 0 seconds. The headline is 8:00.9 per mile. Pace per kilometre is 4:58.8. Speed is 12.05 km/h (7.49 mph). The half-marathon line says 1:45:04.5, four and a half seconds slower than the time you typed, because 13.1 international miles are shorter than 21.0975 kilometres. The marathon line is 3:30:09. The 5K line is 24:54.1.
If you want the projection to equal the time you typed, enter the standard distance. A half marathon in kilometres is 21.0975, not 13.1, and not 21.1 if you care about the last few seconds. The form will accept 21.0975 in the distance field with the unit set to kilometres. It will also accept a track workout. Four hundred metres is 0.4 kilometres. The race lines will still print a marathon at that lap pace, which is a scale, not a suggestion that the lap pace lasts 42 kilometres.
Pace and race times for two 5K finishes and one mile
| Effort you type | Per km | Per mile | 10K | Half marathon | Marathon |
|---|---|---|---|---|---|
| 5 km in 25:00 | 5:00 | 8:02.8 | 50:00 | 1:45:29.3 | 3:30:58.5 |
| 5 km in 30:00 | 6:00 | 9:39.4 | 1:00:00 | 2:06:35.1 | 4:13:10.2 |
| 1 mile in 8:00 | 4:58.3 | 8:00 | 49:42.6 | 1:44:52.5 | 3:29:45 |
What this pace figure leaves out
The projection is the same average pace extended to a new distance. It is not a race predictor. A 5K pace held for a marathon is a much harder effort, and this page has no endurance model, no temperature, and no hills. It also has no stops. If the clock you type includes a minute of standing still, that minute is spread into the average. A moving-time average from a watch can be different. Type the clock you mean.
Distances are exact only if you type them exactly. A certified marathon is 42.195 kilometres. A GPS file can be longer because of corners and drift. The calculator will not correct a GPS distance. Three miles is not a 5K, and 13.1 miles is not a half marathon, as the 1:45:00 example shows. The international mile is not the 1,500 metre metric mile used in track. A 1,500 is 1.5 kilometres. Select kilometres and type 1.5 if that is the race.
Calories are a different question. The calorie calculator estimates maintenance from the Mifflin–St Jeor equation and a multiplier you choose. It does not accept a pace, and this page does not accept a weight. A 25:00 5K and a result of 2,633 calories/day can both be true for the sample inputs on those two pages. Neither number checks the other. BMI is a third calculation, from kilograms and centimetres, and it does not produce a pace.
The display rounds each clock to a tenth of a second after the division. Adding the rounded per-kilometre pace up to a 5K can disagree with the typed time by a tenth. The 5K line for a 5 kilometre entry is the rounded total, so the sample stays 25:00. Very short distances and very long times still divide. A distance of zero, or a time of zero, is rejected. Negative numbers are rejected.
Frequently asked questions
What is the pace for a 25:00 5K?
5:00 per kilometre, which is 8:02.8 per mile. The speed is 12 km/h, or 7.46 mph. At that same pace a 10K is 50:00, a half marathon is 1:45:29.3, and a marathon is 3:30:58.5. The mile factor is 1.609344, so the per-mile clock is not exactly 8:00.
Why is a 5:00 kilometre not an 8:00 mile?
Because a mile is 1.609344 kilometres, not 1.6. Five minutes times 1.609344 is 8 minutes and 2.8032 seconds, which displays as 8:02.8. An actual 8:00 mile is 4:58.3 per kilometre and projects a 5K of 24:51.3. Using 1.6 would make the sample look like 8:00 and would be 3.4 seconds per mile fast on the 30:00 5K as well.
Is 13.1 miles a half marathon on this pace calculator?
No. The half-marathon line uses 21.0975 kilometres. 13.1 international miles are a little shorter, so 13.1 miles in 1:45:00 shows a half-marathon projection of 1:45:04.5 and a pace of 8:00.9 per mile. Type 21.0975 kilometres if you want the standard distance.
Does the 5K pace calculator estimate calories burned?
No. It only divides a time by a distance. The calorie calculator is a separate page, and its sample man at a 1.55 multiplier is 2,633 calories/day whether the 5K was 25:00 or 30:00. A pace is not an activity multiplier, and an activity multiplier is not a finish time.
Can I enter a time as 90 minutes instead of 1 hour and 30 minutes?
Yes. Hours, minutes, and seconds are added. 0 hours, 90 minutes, and 0 seconds is the same total as 1 hour, 30 minutes, and 0 seconds. A total of zero is rejected. The displayed clock then splits that total back into hours, minutes, and seconds, rounded to a tenth of a second.
Related ClearCalc pages
- Daily maintenance calorie calculator Mifflin–St Jeor times an activity multiplier. The sample man at 1.55 is 2,633 calories/day. A 25:00 5K does not change that figure.
- Adult BMI calculator Weight in kilograms and height in centimeters. It does not accept a finish time or produce a pace.
- Length converter from meters If a split was measured in meters, convert it before you type kilometres. This pace page does not convert meters itself.
- Percentage calculator Useful if you already have two paces and want one as a percent of the other. It does not divide a finish time by a distance.