How do you calculate running pace?

Divide your time by the distance. 30 minutes for 5K is 6:00 per kilometre, or 9:39 per mile. To turn it into speed, divide 60 by the pace in minutes: 6:00/km is 10 km/h, and 10:00/mile is 6 mph.

How do I convert minutes per mile to minutes per kilometre?

Divide by 1.609, the kilometres in a mile. 8:00/mile is 4:58/km and 10:00/mile is 6:13/km. The other way, multiply: 5:00/km is 8:03/mile.

What pace do I need for a sub-30 5K, a sub-2 half or a sub-4 marathon?

A sub-30 5K needs 9:39/mile (6:00/km). A sub-2-hour half marathon needs 9:09/mile, and a sub-4-hour marathon the same 9:09/mile held for twice as long. A sub-3 marathon is 6:52/mile. Keep a couple of seconds per mile in hand: GPS over-measures on bends.

How accurate is the Riegel prediction?

Fairly accurate between nearby distances: from a 10K to a half it is usually within a few minutes. The further you stretch it, the more optimistic it gets, especially for the marathon, because it assumes you are as well trained for the longer race. Predict from your longest recent race.

Should I run every mile at the same pace?

Almost always, yes: even splits, or a slightly faster second half (a negative split), is the most efficient way to race. Going out fast is paid back with interest at the end. The splits table gives you the even pace.

What pace should I train at?

Hardly ever at race pace. Most of your volume should be easy, well slower than race pace, and intervals are written as a percentage of your vVO₂max. Measure it with a 6-minute test and you get the pace of all six zones.

Calculator

Running pace calculator

Pace, time or distance: enter two and get the third, in miles or kilometres. Below, the splits to take to the race and what that result predicts for the 5K, 10K, half and marathon.

Your numbers

What do you want to work out?

Unit

Distance

In mi, or pick a race.

Time

h:mm:ss or mm:ss. “50” is 50 minutes.

Calculated in your browser: nothing is sent or stored.

Your pace8:03/mi

Pace: 5:00/km; 8:03/mi
Average speed: 12 km/h; 7.46 mph
Time: 50:00; 50 min
Distance: 10 km; 6.21 mi

Train for that time

The app builds your plan up to race day, with the pace of every rep worked out from your vVO₂max.

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5K to marathon predictions

Riegel formula: T₂ = T₁ × (D₂ ÷ D₁)^1.06. It assumes you are as well trained for the other distance.

Race	Time	Pace
5K	23:59	7:43/mi
10K	50:00	8:03/mi
Half marathon	1:50:19	8:25/mi
Marathon	3:50:01	8:46/mi

Predictions assume you are trained for each distance. Without long runs, a real marathon usually comes out slower than the table.

Even-pace splits

Your time at every mi if you run the whole race at the same pace.

Split	Elapsed
1 mi	8:03
2 mi	16:06
3 mi	24:08
4 mi	32:11
5 mi	40:14
6 mi	48:17
6.21 mi	50:00

How it works

1
Pace = time ÷ distance
Any two give you the third: time = pace × distance, and distance = time ÷ pace. A mile is 1.609 km, so 8:00/mile is 4:58/km.
2
Even-pace splits
Your elapsed time at every mile or kilometre if you ran the whole race at the same pace. The table you write on your wrist or your bib.
3
Prediction with the Riegel formula
T₂ = T₁ × (D₂ ÷ D₁)^1.06. Peter Riegel fitted it in 1981 on running records: double the distance and the time grows a bit more than double, because you hold a smaller share of your maximum.

From race pace to training pace

Race pace is not training pace. These chapters explain where the pace of each session comes from.

vVO2 max: the speed that organizes all your training

What maximal aerobic speed is, how to measure it with a six-minute field test, how all your zones and target paces come out of it, and how often to measure it again.

Keep reading

Training zones: measuring effort without kidding yourself

The three-zone model, where 80/20 comes from, how to estimate your threshold with a field test, and why most recreational runners train in a grey zone that achieves nothing.

Keep reading

VO₂ max and running zones

Your vVO₂max, your six running zones and your estimated VO₂ max.

Keep reading

Frequently asked questions

How do you calculate running pace?: Divide your time by the distance. 30 minutes for 5K is 6:00 per kilometre, or 9:39 per mile. To turn it into speed, divide 60 by the pace in minutes: 6:00/km is 10 km/h, and 10:00/mile is 6 mph.
How do I convert minutes per mile to minutes per kilometre?: Divide by 1.609, the kilometres in a mile. 8:00/mile is 4:58/km and 10:00/mile is 6:13/km. The other way, multiply: 5:00/km is 8:03/mile.
What pace do I need for a sub-30 5K, a sub-2 half or a sub-4 marathon?: A sub-30 5K needs 9:39/mile (6:00/km). A sub-2-hour half marathon needs 9:09/mile, and a sub-4-hour marathon the same 9:09/mile held for twice as long. A sub-3 marathon is 6:52/mile. Keep a couple of seconds per mile in hand: GPS over-measures on bends.
How accurate is the Riegel prediction?: Fairly accurate between nearby distances: from a 10K to a half it is usually within a few minutes. The further you stretch it, the more optimistic it gets, especially for the marathon, because it assumes you are as well trained for the longer race. Predict from your longest recent race.
Should I run every mile at the same pace?: Almost always, yes: even splits, or a slightly faster second half (a negative split), is the most efficient way to race. Going out fast is paid back with interest at the end. The splits table gives you the even pace.
What pace should I train at?: Hardly ever at race pace. Most of your volume should be easy, well slower than race pace, and intervals are written as a percentage of your vVO₂max. Measure it with a 6-minute test and you get the pace of all six zones.

The pace of every rep, already worked out

My PR builds your 5K to marathon plan with the pace of every rep taken from your vVO₂max, and adjusts it every time you retest.

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