Running Pace Calculator
Calculate running pace, time, or distance from any two of the three — with race-time projections for 5K, 10K, half marathon, and marathon.
That's a pace of 5:00/km (8:03/mi) at an average speed of 12.00 km/h (7.46 mph).
Race times at this pace
Results update as you type. Race projections assume even pace — real race times typically slow slightly over longer distances due to fatigue and hills.
Formula
Three identities: pace = time / distance,
time = pace × distance, and
distance = time / pace. The race
projections multiply your pace per kilometre by the four standard distances (5 km, 10 km,
21.0975 km, 42.195 km).
Related calculators
Frequently asked questions
What's a 'good' running pace?▾
Hugely individual — but rough benchmarks for adult runners: 7:30–9:00/km is a comfortable jog for most beginners; 5:30–6:30/km is solid recreational running pace; 4:30–5:00/km is fit-club-runner territory; under 4:00/km is competitive. Heart-rate-based zone training is more useful than pace targets for most beginners — pace varies with heat, terrain, sleep, and stress more than people expect.
How does my pace translate to a marathon time?▾
Multiply pace per km by 42.195. A 5:00/km pace gives ~3h31; 5:30/km gives ~3h52; 6:00/km gives 4h13. Real marathon times typically run 5–10% slower than pure pace × distance because of pacing fade, hills, and aid-station stops. The calculator gives you the pure-arithmetic projection — treat it as a goal pace ceiling, not an expected finish.
Should I train at my race pace?▾
Most evidence-based plans (Daniels, Pfitzinger, Hudson) recommend training at multiple paces: easy (much slower than race pace, building aerobic base), tempo (around lactate threshold, faster than marathon pace), interval (5K-10K race pace), and only occasionally at goal race pace. Spending all your training at race pace tends to cause stagnation and injury risk.
What's the difference between pace and speed?▾
They're inverses. Pace is time per unit distance (e.g. 5 minutes per kilometre); speed is distance per unit time (e.g. 12 kilometres per hour). Runners typically think in pace — it's easier to plan a race ('I'll run 5:30/km splits') than a speed. Cyclists usually think in speed because they're faster overall and the units sit better.
How do I convert pace per km to pace per mile?▾
Multiply by 1.609 (or look at the result above — both are shown). 5:00/km is ~8:03/mile. 6:00/km is ~9:39/mile. The difference matters because British and American running cultures default to opposite units; treadmills, races, and apps don't always align.
Why does this not factor in heart rate?▾
Pace and heart rate are related but not interchangeable — same pace at different temperatures, hills, or sleep states gives very different heart rates. A pace calculator is just arithmetic. Heart-rate-zone training requires individual data (resting and max HR, ideally a lactate-threshold test) and is its own discipline.