FTP Calculator

FTP (Functional Threshold Power) is the highest average power you can sustain for approximately 60 minutes of steady-state effort. For most trained cyclists, FTP correlates strongly with lactate threshold and serves as the anchor for all power-based training zones.

When it's accurate: Your estimate is most reliable when you perform a proper 20-minute all-out test with a 5-minute blowout beforehand (to drain anaerobic capacity). The 20-minute result × 0.95 is the original Hunter Allen/Andrew Coggan method and holds up well against lab testing. The critical-power model is more robust when you have both a 3-minute and 12-minute maximal effort, because it accounts for your anaerobic work capacity (W').

When it's wrong: Ramp tests (e.g. Zwift, TrainerRoad) can overestimate FTP by 5–15% in athletes with strong anaerobic profiles (sprinters, track cyclists) and underestimate in diesel-type endurance athletes who fatigue slowly. A single CP12min value without the 3-minute counterpart ignores your W' — you need both points to fit the curve properly.

Who shouldn't trust this: New cyclists (less than 6 months of structured training) — your maximal efforts won't be truly maximal yet. Riders returning from injury or a long layoff. Anyone who hasn't done a genuine all-out effort in the last 8 weeks. If your test left you questioning whether you could have held 1 more watt, the number is likely low. If you changed position on the bike mid-test, the number is unreliable.

What to do instead: Baseline tracks your best-effort power curves over time and automatically recomputes your FTP from actual race and hard-workout data — no dedicated test required. As your power-duration curve fills in, the estimate gets more accurate.