Pace Lab

Estimates from four published formulas: Riegel's exponent model, Daniels & Gilbert's VDOT, a simple same-pace linear extrapolation, and Purdy's world-record-percentage method — all assuming similar training and conditions across distances. Treat as a guide, not a guarantee — see our methodology.

Even splits hold goal pace throughout. Negative split runs the first half about 4% slower than goal pace and the second half about 4% faster, averaging out to the same finish time.

General guidance, not a training plan -- everyone tapers a little differently.

estimated calories burned

Based on the widely-used running-economy estimate of roughly 1 kcal per kg of body weight per km -- approximately pace-independent at typical training paces. Individual burn varies with fitness, terrain, and conditions.