Running Pace Calculator
Enter any two of distance, time and pace, and the third is calculated live, along with your speed and projected race splits.
| Distance | Time |
|---|---|
| 1 km | 5:00 |
| 1 mi | 8:03 |
| 5K | 25:00 |
| 10K | 50:00 |
| Half marathon | 1:45:29 |
| Marathon | 3:30:59 |
Split times assume a perfectly even pace over the whole distance.
How it works
- Choose what to solve for — pace, finish time or distance — and pick kilometers or miles.
- Fill in the two values you know, or tap a race button like 5K or Marathon to set the distance.
- Read the calculated result instantly, plus your speed and even-pace split times for common race distances.
Frequently asked questions
- How is running pace calculated?
- Pace is simply total time divided by distance, expressed as minutes per kilometer or per mile. If you run 10 km in 50 minutes, your pace is 5:00 min/km. The calculator does this division for you and also rearranges the formula to solve for time or distance when pace is what you already know.
- What is a good pace for a 5K or marathon?
- Recreational runners typically finish a 5K between 6:00 and 7:30 min/km and a marathon between 6:00 and 7:00 min/km, though fitness, age and terrain matter far more than averages. Use the split table to see what a given pace means over each race distance and pick a target that feels sustainable.
- How do I convert pace between min/km and min/mi?
- One mile is 1.609344 km, so multiply a per-kilometer pace by 1.609 to get the per-mile figure — 5:00 min/km equals about 8:03 min/mi. Switching the unit toggle in this tool converts your entered distance and pace automatically, so you never need to do the arithmetic by hand.
- Are the split times realistic for race planning?
- The splits assume a perfectly even pace from start to finish, which is the classic baseline for race planning. Real races usually involve some drift — many coaches suggest running the first half slightly conservatively — so treat the table as a target band rather than a rigid schedule.
- Is my data uploaded anywhere?
- No. Every calculation runs locally in your browser using plain arithmetic — nothing is sent to a server, stored or tracked. You can even load the page, go offline, and keep calculating paces during a flight or in an area with no signal.
About this tool
This running pace calculator solves the three-way relationship between distance, time and pace. Tell it which value you want to find, enter the other two, and the answer appears as you type — no submit button, no page reload. Quick-set buttons for 5K, 10K, half marathon and marathon fill in exact race distances, including the official 21.0975 km and 42.195 km figures, so your numbers match what the finish clock will actually measure.
Everything happens client-side in your browser. The tool converts your inputs to seconds and meters, performs the division or multiplication, and formats the result back into familiar h:m:s and min/km notation. Because there is no server round-trip, results update instantly and none of your training data leaves your device. Switching between kilometers and miles converts your existing distance and pace in place using the exact 1.609344 factor, which avoids the small rounding errors that creep in when people convert by memory.
Beyond the single answer, the calculator shows your equivalent speed in both km/h and mph and builds a split table for common checkpoints: 1 km, 1 mile, 5K, 10K, half marathon and full marathon. This is the fastest way to sanity-check a race goal — if you want a sub-2:00 half marathon, the table shows you must hold roughly 5:41 min/km, and you can immediately see what that pace produces at 5K and 10K along the way.
A few practical tips: treadmills usually display speed rather than pace, so use the km/h and mph readout to translate a workout onto the belt. When planning a race, set your goal time first and solve for pace, then compare that pace against recent training runs at shorter distances. And remember the splits assume even pacing — on hilly courses, budget extra seconds for climbs and recover them on descents rather than chasing a fixed number every kilometer.