Uses the relationship: FTP ≈ 75% of VO₂max power.
VO₂max power (W) = (VO₂max − 7) × weight(kg) / 10.8.
90% CI based on fractional utilization range 70–86% across trained cyclists.
Note on accuracy
This calculator uses the ACSM metabolic equation [1], which was
developed for lab cycle ergometry. Sitko et al. [2] measured FTP
and VO₂max directly in 44 trained road cyclists and found a flatter
relationship: VO₂max = 10.2 × FTP(W/kg) + 12.6. At typical trained
values (~4 W/kg) this calculator estimates ~65 ml/kg/min vs Sitko's
~54 — roughly 20% higher. The gap likely reflects real-world
efficiency losses not captured by the lab equation. Treat these
estimates as approximate upper bounds.
References
[1] ACSM metabolic equation for leg cycling ergometry.
[2] Sitko S, Cirer-Sastre R, López Laval I. "Relationship Between
Functional Threshold Power, VO₂max, and Cycling Performance in Road
Cyclists." Int J Sports Physiol Perform. 2022;17(1):9–15.
Link