Running Pace Calculator
Solve for pace, finish time, or distance: enter any two values and get the third instantly. Switch between three solve modes, pick a race distance preset, and explore your per-kilometer (or per-mile) splits, projected finish times across all major races, and suggested training pace zones.
Formula
Worked example
A 5 km run in 25:00 = 1500 s / 5 km = 300 s/km = 5:00 min/km. Speed = 5 km / (1500/3600) h = 12 km/h. Equivalent in miles: 300 x 1.609 = 483 s/mi = 8:03 min/mile.
How running pace is calculated
Running pace is the time it takes you to cover one unit of distance, found by dividing your total time by the distance you ran. Convert the time to seconds, divide by the distance, then express the result as minutes and seconds per unit. A 5 km run finished in 25 minutes equals 300 seconds per kilometer, written as 5:00 min/km. Pace and speed are two views of the same effort: pace is time per distance (smaller number = faster), while speed is distance per time (larger number = faster). This calculator also solves the two reverse problems: give it a target pace and a distance to predict your finish time, or give it a pace and a time on your feet to work out how far you covered.
Switching between kilometers and miles
One mile equals 1.609344 kilometers, so a per-mile pace is always a larger number than the equivalent per-kilometer pace because a mile is longer. To convert min/km to min/mile, multiply by 1.609344; to go the other way, divide by the same factor. This calculator always shows your pace in both units side by side so you can compare across GPS watches, treadmills, or race programs that use different systems. Speed is shown in both km/h and mph for the same reason.
Race projections and even splits
Once your pace is known, projecting finish times across the classic distances (5 K, 10 K, half marathon, marathon) is a simple multiplication. A 5:00 min/km pace means a 25:00 five-kilometer, a 50:00 ten-kilometer, a 1:45:30 half marathon, and a 3:31:00 marathon. In reality, most runners slow slightly over longer distances due to fatigue, fueling, and pacing strategy, so treat projections as an optimistic baseline and add a conservative buffer for your first attempt at a new distance. The splits table shows the cumulative time you should hit at each kilometer or mile marker to stay on your even-split plan.
Training pace zones based on your current pace
Coach Jack Daniels and McMillan Running both recommend training at effort-based zones rather than a single pace. The easy or long-run zone is roughly 20-30% slower than your current race pace and is where you build aerobic capacity and recover between hard sessions. The tempo or lactate-threshold zone is 5-10% slower than race pace and trains your body to clear lactate more efficiently. Short intervals at or faster than race pace (about 7% faster for VO2 max work) develop maximum oxygen uptake. This calculator estimates all three zones from your current pace so you can structure a complete training week.
Runner level classification
Runners are roughly grouped by pace per kilometer into five levels. Elite runners (under 3:30 min/km for men, roughly equivalent) compete at regional or national level. Fast runners (3:30-4:30 min/km) are competitive club athletes. Intermediate runners (4:30-6:00 min/km) have been running regularly for one to two years and can complete races comfortably. Recreational runners (6:00-8:00 min/km) run for fitness and participate in fun runs and charity events. Beginners (over 8:00 min/km) are in their first months of running. These bands are approximate: age, terrain, heat, and altitude all affect pace significantly.
Pace and projected finish times across major race distances
| Pace (min/km) | Speed (km/h) | 5 K | 10 K | Half marathon | Marathon |
|---|---|---|---|---|---|
| 3:30 | 17.1 | 17:30 | 35:00 | 1:13:33 | 2:27:07 |
| 4:00 | 15.0 | 20:00 | 40:00 | 1:24:24 | 2:48:47 |
| 4:30 | 13.3 | 22:30 | 45:00 | 1:34:57 | 3:09:53 |
| 5:00 | 12.0 | 25:00 | 50:00 | 1:45:30 | 3:30:59 |
| 5:30 | 10.9 | 27:30 | 55:00 | 1:56:03 | 3:52:06 |
| 6:00 | 10.0 | 30:00 | 1:00:00 | 2:06:36 | 4:13:11 |
| 6:30 | 9.2 | 32:30 | 1:05:00 | 2:17:09 | 4:34:18 |
| 7:00 | 8.6 | 35:00 | 1:10:00 | 2:27:42 | 4:55:23 |
| 8:00 | 7.5 | 40:00 | 1:20:00 | 2:48:48 | 5:37:35 |
Projected finish times at a steady pace. Real race conditions will vary.
Frequently asked questions
What is the difference between pace and speed?
Pace is time per unit of distance (minutes per kilometer or mile), while speed is distance per unit of time (km/h or mph). They are mathematical reciprocals: a faster runner has a smaller pace number but a larger speed number. A pace of 5:00 min/km is the same as a speed of 12 km/h.
How do I convert min/km to min/mile?
Multiply your per-kilometer pace by 1.609344, since one mile is 1.609344 km. For example, a 5:00 min/km pace becomes about 8:03 min/mile. To go the other way, divide your per-mile pace by 1.609344.
How can I use my pace to predict a finish time?
Multiply your target pace by the race distance. At 5:00 min/km over 10 km, that is 50 minutes. Most runners hold a slightly slower pace over longer distances, so add 5-10% as a buffer for distances longer than your training runs.
What should my easy run pace be?
Easy runs are typically run at 20-30% slower than your goal race pace. They build aerobic fitness and aid recovery without creating excessive fatigue. If your race pace is 5:00 min/km, your easy pace should be roughly 6:00-6:30 min/km. You should be able to hold a full conversation while running at this effort.
How accurate are race time projections from a training pace?
Projections assume you can maintain the same pace over the full race distance. For short races (5 K, 10 K) where you have recent time-trial data, projections are reasonably reliable within 1-3%. For longer races, fatigue, fueling, pacing strategy, and course conditions create more variability. Treat projections as optimistic targets and build in a conservative buffer.
What is the reverse-solve (distance) mode used for?
If you ran for a set amount of time at a known pace but did not track GPS distance, the distance mode calculates how far you covered. For example, if you ran at a 5:00 min/km pace for 30 minutes, you covered exactly 6 km. This is useful for treadmill workouts or out-and-back routes where you return at the same pace.