BYTETOOLS

Pace Calculator

Calculate running pace, finish time or distance from any two of the three, in min/km or min/mile, with equivalent times for 5K, 10K, half and full marathon.

5:00 /km
Pace per km
8:03 /mi
Pace per mile
12.00 km/h
Speed
7.46 mph
Speed
10.000 km
Distance
50:00
Total time

Equivalent finish times at this pace

DistanceKilometresFinish time
1 kilometre15:00
1 mile1.60938:03
5K525:00
10K1050:00
Half marathon21.09751:45:29
Marathon42.1953:30:59

This table is a straight linear projection — it simply assumes you hold the same pace at every distance. Real sustainable pace drops as races get longer, so the longer entries are an optimistic ceiling rather than a prediction. Proper race predictors apply a fatigue exponent. Training estimates only, not coaching or medical advice.

What is the Pace Calculator?

Running pace is time divided by distance. Covering 10 km in 50 minutes is a pace of 5:00 per kilometre, which is 8:03 per mile and a speed of 12 km/h.

  • Solves for pace, finish time or distance
  • Kilometres and miles, with 5K/10K/half/marathon presets
  • Pace per km and per mile, plus km/h and mph, shown together
  • Equivalent finish times for all standard race distances
  • Per-kilometre and per-mile split reference
  • Runs offline in your browser — nothing is uploaded

How to use the Pace Calculator

  1. 1

    Choose what you want to solve for: pace, time or distance.

  2. 2

    Select kilometres or miles.

  3. 3

    Enter the distance, or pick a race preset.

  4. 4

    Fill in the two values you know — time in h:m:s and pace in min:sec.

  5. 5

    Read the result plus speed and the equivalent race-distance table.

About the Pace Calculator

The ByteTools Pace Calculator solves for whatever you are missing. Give it any two of distance, time and pace and it works out the third — pace from a finished run, the finish time a target pace would produce, or how far you would get in a set time.

Distances can be entered in kilometres or miles, or picked from presets for 5K, 10K, half marathon and marathon. Every result is shown as pace per kilometre and per mile plus speed in km/h and mph, and an equivalent-times table projects your finish at each standard race distance if you held that pace.

It runs entirely in your browser with nothing uploaded. Note that the equivalent-times table is a straight linear projection, not a physiological race predictor — nobody holds 5K pace for a marathon, so treat longer distances as an optimistic ceiling rather than a forecast. These are training estimates only, not coaching or medical advice.

Frequently asked questions

How do I calculate running pace?

Divide your total time by the distance covered. A 50-minute 10 km is 50 ÷ 10 = 5 minutes per kilometre. To convert to miles, multiply the per-kilometre pace by 1.609 — 5:00 per km is about 8:03 per mile.

What is a good running pace?

For recreational runners, 6:00 to 7:00 per kilometre (roughly 9:40 to 11:15 per mile) is a common easy pace, while a sub-5:00 per kilometre 10 km is a solidly trained performance. Pace is highly individual — age, terrain, heat and training history all move it, so compare against your own history rather than anyone else's.

How accurate are the equivalent race times?

The table is a linear extrapolation: it simply assumes you hold the same pace over every distance. That is fine over similar distances but increasingly optimistic as the distance grows, because sustainable pace drops as races get longer. Proper predictors such as Riegel's formula apply a fatigue exponent; treat these figures as a best-case ceiling, not a race plan.

How do I convert min/km to min/mile?

Multiply the per-kilometre pace by 1.60934. A 5:00 per kilometre pace becomes 8.047 minutes per mile, which is 8 minutes and 3 seconds. Going the other way, divide the per-mile pace by 1.60934.

What pace do I need for a sub-4-hour marathon?

Four hours over 42.195 km is 240 ÷ 42.195 = 5:41 per kilometre, or about 9:09 per mile. Enter 42.195 km and a 4:00:00 target time in this calculator to see it worked out along with the split reference.

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