Running Pace Calculator
Solve any one of pace, time, or distance from the other two. Understand the formulas, plan your next race, and know exactly what pace you need to hit your goal.
Standard Race Distances
Race presets (5 km, 10 km, half-marathon, marathon) use the official World Athletics distances — e.g. half-marathon = 21.0975 km exactly.
Flat-Course Assumption
Results assume a flat course and constant pace. Hilly terrain, wind, and fatigue add time. See the Limitations section for correction factors.
What is running pace?
Your quick reference for pace, time, and distance
Running pace is the time required to cover one unit of distance — typically one kilometre or one mile. It is written as min:sec per km (or per mile). A pace of 5:00 min/km means you complete every kilometre in exactly five minutes. Pace is the core metric of every training plan because it directly controls effort level and race strategy.
Quick Answer: Pace = Total Time ÷ Distance. A 50-minute 10 km requires a pace of exactly 5:00 min/km (12.0 km/h / 7.46 mph).
Pace, time, and distance are linked by one simple relationship. Knowing any two of them lets you calculate the third. The calculator converts everything to seconds and kilometres internally, then formats the output as h:mm:ss and min:sec.
Pace (s/km) = Total Time (s) ÷ Distance (km)Total Time (s) = Pace (s/km) × Distance (km)Distance (km) = Total Time (s) ÷ Pace (s/km)Pace and speed are reciprocals: Speed (km/h) = 3 600 ÷ Pace (s/km). A pace of 5:00 min/km (300 s/km) equals 12.0 km/h; a pace of 6:00 min/km equals 10.0 km/h.
Converting pace between km and miles: multiply s/km by 1.609344 to get s/mi. A pace of 5:00 min/km equals approximately 8:03 min/mi.
Suppose you want to run a 10 km in 48:00 (a common intermediate goal). Here is how to use the calculator and verify the math.
Select the mode
Choose Pace from the 'What do you want to calculate?' dropdown. This mode solves for pace given a known time and distance.
Set the distance
Select 10 km from the race preset dropdown. The distance field is automatically filled to 10.0 km exactly (official World Athletics distance).
Enter your goal time
Set Hours = 0, Minutes = 48, Seconds = 0. Total time = 2 880 seconds.
Read the result
Pace = 2 880 s ÷ 10 km = 288 s/km = 4:48 min/km (7:44 min/mi, 12.5 km/h). The result panel shows both min/km and min/mi side by side.
Build your split plan
At 4:48 min/km you should pass each kilometre marker when the clock reads: km 1 → 4:48, km 5 → 24:00, km 10 → 48:00. Use these splits to judge your effort during the race.
The table below lists the pace per km and per mile required to achieve common goal times at the four major road distances. All values are computed from the exact World Athletics distances.
| Goal Time | 5 km Pace | 10 km Pace | Half Marathon Pace | Marathon Pace |
|---|---|---|---|---|
| Sub-20:00 (5 km) | 4:00 min/km | — | — | — |
| 25:00 (5 km) | 5:00 min/km | — | — | — |
| 30:00 (5 km) | 6:00 min/km | — | — | — |
| 45:00 (10 km) | — | 4:30 min/km | — | — |
| 50:00 (10 km) | — | 5:00 min/km | — | — |
| 1:00:00 (10 km) | — | 6:00 min/km | — | — |
| 1:45:00 (half) | — | — | 4:58 min/km | — |
| 2:00:00 (half) | — | — | 5:41 min/km | — |
| 2:30:00 (half) | — | — | 7:06 min/km | — |
| 3:30:00 (marathon) | — | — | — | 4:58 min/km |
| 4:00:00 (marathon) | — | — | — | 5:41 min/km |
| 4:30:00 (marathon) | — | — | — | 6:23 min/km |
| 5:00:00 (marathon) | — | — | — | 7:06 min/km |
Note: Values are computed as goal_seconds ÷ distance_km. For example, 4:00:00 marathon = 14 400 s ÷ 42.195 km ≈ 341.2 s/km = 5:41 min/km.
Running coaches use pace rather than speed because training plans are written in distance units ('run the next 2 km at 5:00 min/km') and GPS watches display lap pace in real time. Speed (km/h) is harder to target accurately on the run because slight changes in incline or wind don't feel like a percentage change in speed — they feel like arriving at your kilometre marker early or late.
Pace and speed are exact reciprocals:
Pace to speed
Speed (km/h) = 60 ÷ Pace (min/km). Example: 5:00 min/km → 60 ÷ 5 = 12.0 km/h. For min/mi: speed (mph) = 60 ÷ Pace (min/mi). Example: 8:00 min/mi → 60 ÷ 8 = 7.5 mph.
Speed to pace
Pace (min/km) = 60 ÷ Speed (km/h). Example: 10.0 km/h → 60 ÷ 10 = 6:00 min/km. For mph to min/mi: Pace (min/mi) = 60 ÷ Speed (mph). Example: 7.5 mph → 60 ÷ 7.5 = 8:00 min/mi.
Flat course only
The calculator assumes a perfectly flat course and constant pace. Real roads have gradients. A rule of thumb from exercise science: every 1 % increase in incline adds roughly 10–15 seconds per km for a moderately fit runner. For trail races or hilly road courses, add 10–20 % to your calculated finish time. The calculator cannot account for cumulative elevation gain.
Constant pace assumption
Most runners do not maintain a perfectly constant pace. The start is often faster due to adrenaline; the final kilometres slower due to fatigue. The calculator gives the average pace needed, not a kilometre-by-kilometre breakdown. For marathon pacing, most coaches recommend starting 5–10 s/km slower than goal pace (negative split strategy) rather than starting at the exact average.
Wind and temperature not modelled
A 5 m/s headwind adds approximately 1–3 % energy cost; high heat and humidity can raise race time by 2–10 % over baseline. These factors are not included — use the calculator for ideal-condition estimates and adjust expectations for adverse weather.