Running Pace Calculator
Calculate pace, finish time, or distance — enter any two and get the third instantly. Works in km or miles.
Running Pace Calculator
Pace · Time · Distance
Whether you're training for a 5K, half marathon, or just your next easy run — knowing your pace lets you train smarter. Use this to project race times, set treadmill speeds, or plan your long run effort levels.
Pace (min/km) = Total time (seconds) ÷ Distance (km) ÷ 60. 1 min/km = 60 km/h speed.
Common Race Distance Reference
| Race | Distance | World Record Pace |
|---|---|---|
| 5K | 5.0 km | ~2:38 min/km |
| 10K | 10.0 km | ~2:41 min/km |
| Half Marathon | 21.1 km | ~2:53 min/km |
| Marathon | 42.2 km | ~2:53 min/km |
Understanding Running Pace: min/km, min/mile, and Speed Conversions
Running pace is the time taken to cover a unit of distance — expressed as minutes:seconds per kilometer (min/km) in metric countries or minutes:seconds per mile (min/mi) in the United States. Speed (km/h or mph) is the reciprocal relationship. These three measurements describe the same thing from different perspectives, but each is more useful in different contexts: pace is preferred for running training (easy to use on a GPS watch to hit targets per km), while speed in km/h is more intuitive for comparing to treadmill settings or general athletic performance benchmarks.
Understanding pace zones is critical for structured running training. Easy/recovery runs should be at 60–70% of maximum heart rate — typically 1–2 min/km slower than your 5K race pace. Tempo runs (lactate threshold training) target 75–85% max HR — a comfortably hard effort you could sustain for 20–40 minutes. Interval training involves 90–100% effort repeats (at or faster than 5K race pace) with complete recovery between efforts. Polarized training — popularized by running coach and researcher Stephen Seiler — structures approximately 80% of volume at easy pace and 20% at hard/threshold pace, which research shows produces superior long-term endurance adaptation compared to mostly moderate-intensity training.
The running pace calculator converts between pace (min/km, min/mi), speed (km/h, mph), and projected race finish times for any distance from 1 mile to marathon. Enter any one variable and get all others instantly. The race time predictor function uses the Riegel formula — a widely-used endurance performance prediction model — to estimate your finish time at longer distances from your current performance at a shorter distance. The formula assumes a fatigue factor across distances, which has been validated against real race data from recreational through elite runners.
Training Pace Zones
Easy runs should be 1–2 min/km slower than your 5K race pace. Tempo runs are at your ~1-hour race pace. Intervals are at or faster than 5K pace. Mix these throughout the week for balanced development.