Cameron Race Time Predictor Calculator

About this calculator

The Cameron formula, developed by running statistician Dave Cameron in the 1990s, predicts a runner's finish time at one distance from a known result at another using a slightly non-linear model rather than a simple proportional scale-up: T2 = T1 × [(D2/D1) + 0.0654 × (1 − D2/D1)] for the standard version, which accounts for the fact that pace naturally slows as distance increases, making it more accurate than a flat multiplier across widely different race distances like a 5K to a marathon.

This calculator takes a known race distance and time along with a target distance and returns the predicted finish time. Runners setting a goal pace for an upcoming race and coaches building training plans around realistic time targets use it — alongside similar formulas like Riegel's — to translate recent race fitness into an expectation for a different distance, while acknowledging that specific endurance and training for the target distance still matter.