Running Pace Calculator
Pace is the runner's shared language — "5-minute Ks" says more than any speed number. Enter any distance and finish time (h:mm:ss, the format GPS watches report) and this calculator returns pace per kilometer and per mile in that same clock format, plus your speed in km/h and mph for treadmill cross-checks.
The prediction row is the training payoff: it scales your current pace across the classic race distances — 5K, 10K, half and full marathon — so a single hard 10K instantly becomes a realistic marathon target conversation. It assumes the same pace holds (not a fatigue-adjusted projection, which elite tools model), making it most accurate from threshold work up to about the half marathon. Logs pair well with the sleep cycle calculator, because recovery is the other half of pace.
How to use
- Choose kilometers or miles, enter your distance and finish time — pace per km and per mile appear instantly.
- Read the predicted finish times for 5K, 10K, half and marathon at that same pace.
- Share the result with one tap — the link carries your run so training buddies see identical numbers.
Frequently asked questions
How do I calculate my running pace?
Divide your finish time by the distance: a 52:30 10K is 3150 seconds ÷ 10 km = 5:15 per kilometer (about 8:26 per mile). The calculator does the division in both units at once and works for any distance you enter, from a track mile to an ultramarathon.
What is a good running pace?
Recreational 5K paces commonly fall between 5:00 and 7:30 per kilometer (8:00-12:00 per mile), while sub-20-minute 5K racing means holding 4:00/km or faster. "Good" is trajectory, not a table — compare against your own last month, and the prediction row shows what your current pace already buys at longer distances.
How accurate are race predictions from pace?
Same-pace scaling is solid up to about the half marathon; beyond that, fatigue, fueling and heat push real times slower than linear math. Treat the marathon row as a fit-runner's floor, then adjust for course, weather and long-run experience.
What pace should I train at?
Most weekly mileage should be conversational — typically 60-90 seconds per kilometer slower than your 5K race pace — with one or two quality sessions faster. Enter a recent race above, then run easy days about 1:30/km slower than the pace shown.