This calculator estimates the impact of moderate weight loss (mainly reliable up to 5% of body
weight)
on your running speed and time per kilometer.
For the calculation to be correct, it must be excess weight compared to race weight.
Enter your weight and reference pace
Estimated results
Relative loss
-- of body weight
Estimated new pace
--:-- min/km
Time gain per km
-- s/km
Gain on a 10 km race
--
Time gained by distance
Time you will save on each distance with this weight loss.
Marathon impact by weight loss
See how much time you could save on a marathon by losing 1 to 10 kg.
Details on the model used
This approximation comes from physiological analyses: in running, carrying less mass
costs slightly less energy, which allows running slightly faster at equal intensity.
The 1% weight lost ≈ 1% speed gained relationship is mainly valid for modest losses (up to ~5%).