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🏃 Free Pace Calculator

Running Pace Calculator — Pace, Speed & Race Predictor

Enter any distance and time to get your pace, speed, and predicted finish times for 5K, 10K, half marathon and marathon. Plus training pace zones for your goal.

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🏃 Running Pace & Race Time Calculator

Enter your distance and time — get pace, speed, and predicted race finish times

min/km

Your Results

Pace (per km)
Pace (per mile)
Speed
Distance

🏁 Predicted Race Finish Times

DistancePredicted TimePace/km

Predictions use the Riegel formula — most accurate within ±5% for similar distances. Longer extrapolations carry more uncertainty.

🎯 Training Pace Zones (based on your pace)

⚠️ Race predictions assume similar training and conditions. Heat, hills, and race-day factors significantly affect actual performance.

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Running Pace — Complete Guide

Pace is the time it takes to cover a fixed distance — typically expressed as minutes per kilometre or minutes per mile. Understanding your pace helps you train at the right intensity, pace races correctly, and track improvement over time.

Common Race Pace Targets

Goal Time5K Pace/km10K Pace/kmHalf Marathon Pace/kmMarathon Pace/km
Sub-30 (5K)5:59
Sub-25 (5K)4:59
Sub-50 (10K)4:59
Sub-2:00 (HM)5:41
Sub-4:00 (Marathon)5:41
Sub-3:30 (Marathon)4:58

Why Use the Riegel Formula for Predictions?

The Riegel formula (T2 = T1 × (D2/D1)^1.06) accounts for the fact that pace naturally slows over longer distances due to fatigue and fuel depletion. It is the most widely used race prediction formula in exercise science, accurate to within 3-5% for trained runners across similar distance ranges.

For best accuracy, predict races within 2x your tested distance — predicting a marathon from a 5K time carries more uncertainty than predicting a 10K from a 5K time.

Frequently Asked Questions

The most effective ways to improve pace are: building an aerobic base with Zone 2 training (read our Zone 2 guide), adding tempo runs at slightly faster than race pace, and interval training to raise VO2 max (see our VO2 max guide). Consistency over months matters more than any single workout.
Most marathon training should be 20-30 seconds per km slower than goal marathon pace (easy/Zone 2 runs). Long runs are typically done at or slightly slower than marathon pace. Speed work (intervals, tempo) should be faster than marathon pace. Only a small percentage of total training volume should be at actual race pace.
The Riegel formula is accurate within 3-5% for predictions across similar distances (e.g., 5K to 10K) for trained runners. Predictions become less accurate for very different distances (5K to marathon) because endurance and pacing strategy differ significantly. Use predictions as a guide, not a guarantee.