A guide to the formulas and logic used in each tool.
Uses Jack Daniels’ VDOT method. Intervals are converted into outdoor-equivalent VO₂ using the ACSM running equation:
VO₂ (ml/kg/min) = 3.5 + 0.2 × speed (m/min) + 0.9 × speed × grade
Average VO₂ is mapped to VDOT, then used to predict 5K, 10K, half marathon, and marathon times.
Based on VO₂ → METs conversion. 1 liter of O₂ ≈ 5 kcal.
Converts treadmill speed + incline to outdoor-equivalent flat pace, solving ACSM in reverse.
km/h = mph × 1.609
Finds treadmill speed at chosen incline that matches the VO₂ cost of your outdoor pace.
Estimates vertical climb:
Climb (m) = Distance (km) × 1000 × (Incline % / 100)
Example: 5 km at 5% = 250 m climb.