AI FTP & VDOT Estimator
Combine your cycling test data with race results for a confidence-weighted fitness estimate. See your W/kg category and running VDOT side by side.
FAQ
Which FTP test is most accurate?
The 20-minute test (95% of average power) is the gold standard. The 8-minute test tends to overestimate for less trained athletes, and ramp tests can be affected by anaerobic capacity. We adjust each with standard scaling factors.
What do the W/kg categories mean?
They follow Coggan's classification: Cat 5 (<2.5), Cat 4 (2.5-3.2), Cat 3 (3.2-3.8), Cat 2 (3.8-4.4), Cat 1 (4.4-5.0), and Pro (>5.0 W/kg). These are based on male thresholds.
Why combine FTP and VDOT?
Many triathletes and multi-sport athletes need both metrics. Combining them in one tool with a shared confidence score gives you a holistic view of your cycling and running fitness.
Methodology
FTP is estimated using Coggan's standard scaling: 95% for 20-min, 90% for 8-min, 75% for ramp tests. VDOT uses the Jack Daniels formula relating race speed to VO2max fraction sustained. Confidence score is 60% with one data source, 80% with two, and 95% with three or more.
Want to verify the math?
Explore 170+ reference calculators built by engineer-athlete Thomas Prommer. The technical foundation behind our AI.
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