How do I calculate my running pace?
Divide total time by total distance. For example, 30 minutes for 5 km = 6 minutes per km. Use a pace calculator or GPS watch to do this automatically. To predict race times, use VDOT tables or a race predictor tool based on a recent race result.
The basic math is simple: pace = time ÷ distance. If you ran 5 km in 30 minutes, your pace is 30 ÷ 5 = 6 minutes per kilometer. If you ran 10 km in 55 minutes, your pace is 55 ÷ 10 = 5:30/km. Every GPS running watch does this automatically. For race planning, you need the reverse — 'what finish time does this pace produce at this distance?' — which requires multiplying pace by distance. A 5:30/km pace over 21.1 km (half marathon) is 5.5 × 21.1 = 116.05 minutes = 1 hour 56 minutes. Online pace calculators and watches do this instantly. For predicting what time you can run at an untested distance, use VDOT tables (Jack Daniels' method) or race equivalency calculators. These take your recent race result and predict times for other distances based on physiological scaling. Rough rule of thumb: your marathon pace is typically 25-35 seconds per km slower than your half marathon pace. Don't confuse current pace (what you ran today) with race pace (what you can sustain) — the two are different. A pace you can hold for 10K in training is roughly your 10K race pace; pace calculators don't know your fitness, they just convert numbers.