Weight Loss Running Pace Calculator
Explore how a user-selected change in non-functional body mass could affect race time if aerobic fitness otherwise stays unchanged.
Predicted performance
How this estimate works
The calculator estimates current VDOT from distance and finish time. It then models a target relative VDOT as current VDOT × current weight ÷ target weight and uses a binary search to find the time producing that VDOT over the same distance. This is not a guarantee or target-weight recommendation.
Important limitations
This estimate assumes fitness and absolute aerobic capacity remain unchanged and that the weight change is primarily non-functional mass. Losing muscle, glycogen, blood volume, or other functional tissue can reduce performance. Running economy does not change perfectly in proportion to bodyweight, and larger changes are less reliable. Terrain, heat, altitude, training, fatigue, and fueling also affect race performance.