Running Pace Calculator

Running pace calculator for miles, kilometers, and race finish times

This running pace calculator turns distance and elapsed time into pace per kilometer, pace per mile, average speed in kilometers per hour, and speed in miles per hour. It also projects equivalent 5K, 10K, half-marathon, and marathon finish times at the same average pace. Use it after a run, when building a race pacing plan, or when converting a treadmill speed into a more familiar min/km or min/mile target.

Running pace formula

Pace = total time ÷ distance

Speed = distance ÷ time

Pace and speed describe the same performance in opposite ways. A lower time per mile or kilometer is faster, while a higher mph or km/h speed is faster. For accurate results, enter moving time if you want your running pace, or total elapsed time if you want a race-style pace that includes every stop.

10K pace example

Completing 10 kilometers in 50 minutes gives 50 ÷ 10 = 5:00 per kilometer. Ten kilometers equals about 6.214 miles, so the same run is approximately 8:03 per mile. Average speed is 12 km/h or about 7.46 mph. At a perfectly even 5:00/km pace, a 5K takes 25:00 and a half marathon takes roughly 1:45:29.

Common race distances

Pace needed for common finish-time goals

A sub-30-minute 5K requires an average pace just under 6:00/km or 9:39/mile. A 60-minute 10K is exactly 6:00/km. A two-hour half marathon needs approximately 5:41/km or 9:09/mile, while a four-hour marathon requires about 5:41/km as well. Real courses, aid stations, hills, weather, and GPS measurement can all shift the final time, so a race plan often includes a small buffer rather than targeting the exact mathematical pace.

How to convert pace per kilometer to pace per mile

One mile is 1.609344 kilometers. Multiply the number of seconds per kilometer by 1.609344 to get seconds per mile. For example, 4:30/km is 270 seconds; 270 × 1.609344 = 434.5 seconds, or about 7:15/mile. To convert pace per mile to pace per kilometer, divide seconds per mile by 1.609344.

Why a simple race projection may be optimistic

The race table assumes you can hold the entered pace for every distance. That is useful for an even-pace schedule but is not a physiological race predictor. A pace sustained for 5K will usually not be sustainable for a marathon without adjustment. Training volume, recent race results, terrain, heat, hydration, fueling, fatigue, and recovery all affect performance. Treat longer-distance finish times as pace equivalents, not promises.

Using pace in training

• Easy runs: use a conversational effort rather than forcing a race-goal pace.
• Intervals: calculate each repetition from its distance and target pace.
• Tempo runs: compare average pace across similar routes and conditions.
• Race planning: translate a finish-time goal into mile or kilometer splits.

Pace chart: what each pace means over a race

A pace chart turns one number into finish times, which is the form most runners actually think in. These assume an even effort the whole way — see the note above on why a real race rarely holds that.

What pace do I need for a two-hour half marathon?

A two-hour half marathon needs 5:41 per kilometre, or 9:09 per mile, held across all 21.0975 km. It is the most common target in road running because it sits just far enough above a casual pace to require training, and the arithmetic is unforgiving: drifting 10 seconds per kilometre slower costs you three and a half minutes, and the finish goes with it.

The usual mistake is banking time early. Starting at 5:25 and fading to 6:00 gives a slower finish than running 5:41 throughout, because the fade lasts longer than the surplus did.

Converting between min/km and min/mile

A mile is 1.609344 km, so pace converts by multiplying the per-kilometre time — in seconds — by that same factor.

sec per mile = sec per km × 1.609344

Convert to seconds first, then back to minutes and seconds. Multiplying 5:00 by 1.61 as a decimal gives 8.05, and reading that as 8:05 is wrong — the correct answer is 8:03, because 0.05 minutes is 3 seconds, not 5.

Running pace is only one training signal and is not medical advice. For general daily energy planning, use the calorie and macro calculator. To compare how much a finish time improved between two races, use the percentage change calculator and remember that a lower time represents better performance.