"What's your pace?" is the runner's most common conversation. It's also the single most useful number in training — more useful than total mileage, because it controls how hard each run actually is. The math is simple division, but the practical applications (target pace for a goal time, conversion between metric and imperial, comparing efforts at altitude) are where it pays off.
The pace formula
Pace = Time ÷ Distance
That's it. The trick is keeping the units consistent. If your time is in minutes and your distance is in miles, your pace is in minutes per mile. If you ran 3.1 miles (a 5K) in 27 minutes:
Pace = 27 ÷ 3.1 = 8.71 min/mile = 8:42 per mile (the 0.71 of a minute is 0.71 × 60 = 43 seconds; rounded to 42 it reads more naturally)
Converting between min/mile and min/km
1 mile = 1.609 km, so:
- min/mile → min/km: divide by 1.609
- min/km → min/mile: multiply by 1.609
An 8:42 mile pace is 8:42 ÷ 1.609 = 5.41 min/km = 5:25 per km. A 5:00 km pace is 5 × 1.609 = 8.045 min/mile = 8:03 per mile.
Pace bands for common race times
Memorize a few of these and you can size up any race instantly:
- Sub-20 5K: 6:26/mile — 4:00/km
- Sub-25 5K: 8:03/mile — 5:00/km
- Sub-30 5K: 9:39/mile — 6:00/km
- Sub-50 10K: 8:03/mile — 5:00/km
- Sub-2:00 half-marathon: 9:09/mile — 5:41/km
- Sub-1:45 half-marathon: 8:01/mile — 4:59/km
- Sub-4:00 marathon: 9:09/mile — 5:41/km
- Sub-3:30 marathon: 8:00/mile — 4:58/km
- Sub-3:00 marathon: 6:52/mile — 4:16/km
Pace vs splits
A "split" is your pace over a specific segment — usually each mile or kilometer. Even pacing means every split matches your average. Negative splits mean the second half is faster than the first; this is the gold standard for distance racing because it conserves glycogen and minimizes the late-race fade. Positive splits (slowing down) usually mean you went out too hard. Most personal-record performances at any distance over a mile are run with even or slightly negative splits.
Goal pace from goal time
Working backward is just as easy. If your goal is a sub-4:00 marathon (3:59:59 over 26.2 miles):
Pace = 240 minutes ÷ 26.2 = 9.16 min/mile = 9:09 per mile. Run faster and you've got buffer; run slower at any point and you've spent it.
Adjusting for hills and heat
Pace is honest only on flat ground in cool weather. Common adjustments:
- Each 1% grade uphill: add roughly 12–15 seconds per mile
- Each 1% grade downhill: subtract 8 seconds per mile (gentle downs help; steep downs hurt)
- Above 60°F (15°C): add roughly 1% to expected time per 5°F above 60°F
- Wind: 10 mph headwind costs roughly 6–10 seconds per mile; tailwind gives back about half
Using a calculator
Our running pace calculator handles three modes: enter any two of pace, time, and distance, and it solves for the third. It's the fastest way to plan a workout (target pace for X miles) or analyze a race (what pace did I just run).