Pace Calculator
Calculate your running or walking pace, total time, or distance. Enter any two values to find the third. See projected finish times for common race distances based on your pace.
Pace is the language of running. While speed (miles per hour) makes sense for cars, runners think in minutes per mile or minutes per kilometer because pace times the distance gives the finish time directly. A 9:00 min/mile pace over 26.2 miles is a 3:55:30 marathon — no extra math required.
This calculator handles all three sides of the pace/time/distance relationship: enter any two, get the third. It also projects finish times for common race distances (5K, 10K, half marathon, marathon) based on your input pace, useful for setting target paces in training or seeing how your easy-run pace would translate to a race.
The same math applies to walking, cycling, swimming, and any constant-speed effort. The "good pace" benchmarks differ by sport — what's slow for a runner is fast for a walker — but the conversion formula is identical.
Inputs
Results
Pace
8:04 /mile
Speed
7.44 mph
Total Time
25:00
Race Projections at Current Pace
| Race | Miles | Projected Time |
|---|---|---|
| 1 Mile | 1 | 8:04 |
| 5K | 3.107 | 25:03 |
| 10K | 6.214 | 50:07 |
| Half Marathon | 13.109 | 1:45:43 |
| Marathon | 26.219 | 3:31:27 |
Formula
How to use this calculator
- Enter any two of distance, time, and pace. The third is computed.
- For time, use hours + minutes + seconds. A 5K finish of 25:00 is "0 hours, 25 minutes, 0 seconds."
- Distance is in miles by default. To convert from kilometers, multiply by 0.6214 (e.g., 10K = 6.21 miles).
- Use the projected finish times for common distances to translate your training pace into race targets.
- For interval training, calculate pace per 400m or 800m and then project full mile time to set targets.
Worked examples
Marathon goal at 9:00 pace
Goal pace: 9:00 min/mile Distance: 26.2 miles (marathon) Finish time: 26.2 × 9 = 235.8 minutes = 3:55:48 For most amateur runners, sub-4-hour marathon is a major milestone. Sub-3 takes serious training; sub-2:30 is competitive.
5K time predicts other distances
Recent 5K time: 22:30 (7:15 min/mile pace) Projected at the same pace: 10K: 45:00 Half marathon: 1:34:55 Marathon: 3:09:51 Real race times slow at longer distances due to glycogen depletion and pacing fatigue. Common adjustments: +5–10 seconds per mile for 10K, +20–30 sec for half, +30–60 sec for marathon.
When to use this calculator
Use this for training pace planning, race goal projection, treadmill workouts, and pace-grouping in group runs. The calculator works for any sport with constant-speed movement; just remember "pace" conventions differ — runners use min/mile, cyclists use mph or km/h, swimmers use seconds per 100 yards/meters.
For predicting race times from training paces, use known finish-time conversion formulas (Riegel's formula is a common one: T2 = T1 × (D2/D1)^1.06). For heart-rate-based training zones, see the heart rate zone calculator.
Common mistakes to avoid
- Confusing pace (min/mile) with speed (mph). They're inverses; fast pace = low number, fast speed = high number.
- Adding paces. Pace doesn't average linearly across distance segments at different speeds. Total time = sum of segment times; recompute pace from the total.
- Forgetting unit conversion. 5K races measure 3.1069 miles (not 5 miles), and a 10K is 6.21 miles.
- Comparing treadmill pace to outdoor pace directly. Treadmills typically run "easier" than outdoor at the same speed setting because there's no wind resistance and the belt assists.
- Linear-projecting a 5K pace to marathon. Most runners slow 5–15% from 5K pace over a marathon due to glycogen depletion and pacing.
Frequently Asked Questions
Sources & further reading
- Pace calculator (USA Track & Field) — USA Track & Field
- Riegel race-time prediction formula — Runner's World