Enter your run distance (5K, 10K, Half Marathon, Full Marathon, or custom distance) and finish time to calculate your exact running pace (/km and /mi), average speed, and race time projections.
How to use this calculator
Select a standard race distance preset (5K, 10K, Half Marathon, Marathon) or choose Custom Distance.
Enter your total completion time in hours, minutes, and seconds.
Read your average running pace per kilometer (e.g. 5:00 /km) and per mile (e.g. 8:03 /mi).
Review your average speed in km/h and mph, alongside projected equivalent race finish times.
Formula & method
Pace & Speed Equations
Pace (sec/km) = Total Seconds ÷ Distance (km) · Speed (km/h) = Distance (km) ÷ (Total Seconds ÷ 3600)
5K = 5.0 km, 10K = 10.0 km, Half Marathon = 21.0975 km, Marathon = 42.195 km.
Running pace is expressed as minutes and seconds per unit distance (min/km or min/mi), which remains linear unlike speed.
A 5:00 /km pace equals exactly 12.0 km/h (7.46 mph) and results in a 25:00 5K finish time.
Even pacing (maintaining constant speed throughout a race) is statistically proven to maximize endurance performance.
Positive splitting (starting too fast and slowing down) wastes glycogen early, whereas negative splitting (finishing faster than starting) conserves energy.
Pace conversion: multiply min/km by 1.60934 to find min/mi (e.g. 5:00 /km × 1.609 = 8:03 /mi).
How to interpret your result
Running Pace vs. Speed
Pace measures time per distance (min/km), making it easier for runners to track lap splits than speed (km/h).
Race Time Projections
Projected race times assume equivalent cardiovascular fitness across distances without accounting for endurance decay over longer events.
Pacing Strategy
Use your calculated pace targets to structure interval training, tempo runs, and long-run pacing zones.
Frequently asked questions
How do I calculate running pace?
Divide your total run time in seconds by the distance ran, then convert the remaining seconds into minutes and seconds format.
What is a good 5K running pace for beginners?
A pace of 6:00 to 7:00 /km (9:40 to 11:15 /mi) is typical for beginner runners, resulting in a 30 to 35-minute 5K finish.
How do I convert min/km to min/mi?
Multiply your pace in decimal minutes per kilometer by 1.609344 to get decimal minutes per mile.
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