Running Pace Calculator — Race, Marathon & Training Pace
This free running pace calculator works out your pace, time, or distance from any two values, then projects finish times for every major race. Whether you need your race pace for an upcoming 5K, your goal marathon pace, a 10K pace target, or a simple running pace for daily training, the math is the same: Time = Distance × Pace. Enter two fields and the third is solved instantly in min/mile or min/km.
How to use this pace calculator
- Pick your unit. Toggle between Miles and Kilometers at the top.
- Tap a race preset (1 Mile, 5K, 10K, Half, Marathon) to fill the distance instantly — or type any custom distance.
- Enter any two fields. Fill in two of distance, total time, and pace — leave the one you want to find blank.
- Read your results. You get your pace in both min/mi and min/km, your speed in mph and km/h, fatigue-adjusted race predictions, training pace zones, and a split table.
- Set a goal. To find a target pace, enter a race distance and your goal finish time — the tool returns the pace you must hold and the splits to check against your watch.
Common race distances
- 5K = 3.107 miles (5 km)
- 10K = 6.214 miles (10 km)
- Half Marathon = 13.109 miles (21.098 km)
- Marathon = 26.219 miles (42.195 km)
Pace chart: what each pace means at the finish line
| Pace /mi | 5K | 10K | Half | Marathon |
|---|---|---|---|---|
| 7:00 | 21:45 | 43:30 | 1:31:46 | 3:03:31 |
| 8:00 | 24:51 | 49:43 | 1:44:52 | 3:29:45 |
| 9:00 | 27:58 | 55:56 | 1:57:59 | 3:55:58 |
| 10:00 | 31:04 | 1:02:09 | 2:11:05 | 4:22:11 |
| 11:00 | 34:11 | 1:08:22 | 2:24:12 | 4:48:25 |
| 12:00 | 37:17 | 1:14:34 | 2:37:19 | 5:14:38 |
Marathon and half marathon pace goals
Popular targets are the sub-2:00 half marathon (about 9:09 per mile) and the sub-4:00 marathon (about 9:09 per mile as well, held for 26.2 miles). A 5:00-per-mile pace is elite territory. Because fatigue builds over distance, most coaches suggest training slightly faster than goal pace on short intervals and slightly slower on long runs.
Note on predicted times
Race predictions use the Riegel formula (T₂ = T₁ × (D₂/D₁)1.06), the same fatigue model used by coaches and major running publications — so a longer race is predicted slightly slower per mile than your current effort, not naively extrapolated at even pace. Terrain, heat, and race-day conditions still matter, so treat predictions as a well-informed baseline.
Methodology & sources
Solver: Time = Distance × Pace; any two values determine the third. Race predictions: Riegel endurance model with exponent 1.06 (Peter Riegel, Runner's World, 1977 — "Athletic Records and Human Endurance," also published in American Scientist, 1981). Training zones: offsets from your Riegel-equivalent 5K pace — easy +90–120 s/mi, long run +60–90 s/mi, tempo/threshold +25–30 s/mi, 1600 m intervals −5–10 s/mi — consistent with widely used coaching guidance (Daniels' Running Formula). Splits: even-pace cumulative times. Last reviewed: by the Toolchive Team.
Running pace calculator variants — find your pace for any race or workout
5K pace calculator
For a 5K race (3.107 miles), use this calculator to find how fast you need to run to hit your goal finish time. For example, if you want to break 25 minutes on a 5K, the calculator returns the pace (about 8:02 per mile). Most recreational runners target a 25–35 minute 5K, which translates to 8:00–11:15 per mile pace.
10K pace calculator
A 10K (6.214 miles) is usually run somewhat slower than 5K pace because of the longer distance. If your 5K pace is 8:00 per mile, a starting estimate for sustainable 10K pace might be 8:20–8:40 per mile, depending on endurance and conditions. Use the calculator to check: enter a goal 10K time (for example, 55 minutes) and distance (10 km), and find the exact pace to maintain.
Half marathon pace calculator
Half marathons (13.1 miles / 21.1 km) demand a longer sustainable pace. A sub-2:00 half marathon requires a 9:09 per mile pace for the full distance. Many runners aim for 1:45–2:15, which corresponds to 8:00–10:30 per mile. Enter your goal finish time and this calculator returns the pace you must hold for 13.1 miles.
Marathon pace calculator
The full marathon (26.2 miles / 42.2 km) is where pacing strategy matters most. A 4-hour marathon (a common recreational goal) requires 9:09 per mile for the full distance. Elite amateurs run closer to 6:00–7:00 per mile, while recreational runners often target 9:00–11:00 per mile. The calculator helps you find the exact pace for your goal time, then check how that pace projects to shorter race distances.
Race pace vs. training pace
Race pace is the speed you aim to hold during an actual race, while training pace is typically slower. Long slow distance (LSD) runs are usually 60–70 seconds per mile slower than race pace, while tempo runs are 20–30 seconds slower. Use the calculator to experiment: if your goal 5K pace is 8:00/mile, your long run pace might be 9:00–9:30/mile.
Tempo run pace and threshold pace
Threshold pace (also called lactate threshold or "comfortably hard" pace) is about 25–30 seconds per mile slower than 5K pace. If your 5K pace is 8:00/mile, threshold pace is around 8:25–8:30/mile — pace you can hold for about 20–30 minutes. The calculator helps you find this by solving for the pace that matches your goal time on a 30–40 minute workout.
Easy run pace
Easy runs should be 90–120 seconds per mile slower than race pace to allow recovery. If your 5K pace is 8:00/mile, easy pace should be 9:30–10:00/mile. Many runners run too fast on easy days; this calculator helps verify your easy pace is genuinely easy.
Pace calculator for mile and 800m
For track runners, the mile and 800m are classic distances with their own pace targets. A 6:00 mile requires a 6:00 per mile pace (obviously), but understanding your mile pace can help you estimate longer-distance targets. A 5K pace must be slower than an all-out mile pace; as a rough starting point, multiplying mile pace by about 1.08–1.12 gives 6:29–6:43 per mile for a 6:00 miler. Actual 5K pace varies with endurance and training, so use a recent race or time trial when possible.
Pace converter — min/mile to min/km
To convert min/mile to min/km, divide by 1.609 (the km-per-mile ratio). For example, 8:00/mile ÷ 1.609 = 4:58/km. The calculator toggles between miles and kilometers instantly, so you can compare paces regardless of unit.
Calculate pace for tempo runs and speed work
Interval training (400m, 800m, 1600m repeats) and tempo runs use different paces:
- 400m repeats: usually 10–20 seconds per 400m faster than 5K pace
- 800m repeats: usually 5–10 seconds per 400m faster than 5K pace
- 1600m repeats (mile): usually 5–10 seconds per mile faster than 5K pace
- Tempo runs: 25–30 seconds per mile slower than 5K pace
Use the calculator to convert these to your goal paces and check them against actual race projections.
Frequently asked questions
How does this pace calculator work?
Enter any two of distance, time, and pace, and the pace calculator solves for the third. It then projects your finish times for common races like the 5K, 10K, half marathon, and marathon.
How do I calculate running pace?
Pace is your time divided by distance, such as minutes per mile or per kilometer. Enter a run's distance and total time and the tool returns your pace automatically.
Can it predict my race finish time?
Yes. It uses the Riegel formula (exponent 1.06) to predict fatigue-adjusted finish times for the 5K, 10K, half, and full marathon from your current effort — the same model coaches use, more realistic than assuming you hold an identical pace forever.
What is a good marathon pace?
A 4-hour marathon is about 9:09 per mile (5:41 per km), a common goal for recreational runners. Elite men hold close to 4:41 per mile. Enter your goal finish time against the marathon distance and the calculator returns the exact pace you need.
How do I convert min/mile to min/km?
Switch the distance unit toggle between Miles and Kilometers and your pace recalculates instantly. As a rule of thumb, min/km is roughly min/mile divided by 1.609 — for example 8:00/mile is about 4:58/km.