Running Pace Calculator
Whether you are training for a race or tracking your fitness, knowing your pace is essential. Enter your distance and time to calculate your pace, speed, and predicted finish times for standard race distances using the Riegel race prediction formula.
Running pace is typically expressed as minutes per kilometer (min/km) or minutes per mile (min/mi). It is the inverse of speed and gives runners a practical measure of how fast they are covering distance. Most runners find it easier to think in terms of pace rather than speed when planning training sessions and race strategies.
The race predictions use the Riegel formula (T2 = T1 x (D2/D1)^1.06), developed by Peter Riegel in 1977 and refined over decades. This formula accounts for the fact that running pace naturally slows as distance increases, using an exponent of 1.06 to model this fatigue factor. The formula is most accurate when predicting races of similar length to your input distance.
For competitive runners, pace training zones are typically defined relative to race pace: easy runs at 60-70% effort (about 60-90 seconds slower per km than race pace), tempo runs at 80-90% effort (about 15-30 seconds slower), and interval training at 95-105% of race pace. Understanding your current pace allows you to set appropriate training intensities for improvement.