RUNNER TOOLS
RACE TIME PREDICTOR
Ran a recent race? See what it predicts for every other distance.
5K
0:23:59
10K (your result)
0:50:00
Half Marathon
1:50:19
Marathon
3:50:01
Uses the Riegel formula (T2 = T1 × (D2/D1)^1.06), a widely used endurance-performance estimate. It assumes similar training and conditions across distances — treat it as a reasonable guide, not a guarantee.
Works best when the known result is reasonably recent and well-paced.