Cycling W/kg & FTP Zones Calculator
Enter your FTP and body weight to get your power-to-weight ratio and the exact watt ranges for all six training zones.
Power-to-weight ratio
– W/kg
Your FTP training zones
| Zone | % of FTP | Watts |
|---|---|---|
| Z1 Active Recovery | < 55% | – |
| Z2 Endurance | 55–74% | – |
| Z3 Tempo | 75–89% | – |
| Z4 Lactate Threshold | 90–104% | – |
| Z5 VO2 Max | 105–120% | – |
| Z6 Anaerobic Capacity | > 120% | – |
Stop memorizing your FTP zones.
Type your next session in your own words — “4 x 5 min at Zone 4 with 3 min easy” — and TextFit puts the exact watt targets on your Wahoo or Garmin.
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How the calculation works
Your power-to-weight ratio is your FTP in watts divided by your body weight in kilograms. It's the number that levels the playing field between riders: on a climb, a 60 kg rider holding 240 W matches a 90 kg rider holding 360 W — both at 4.0 W/kg. That's why racers and climbers obsess over watts per kilo rather than raw power.
The training zones follow the widely used Coggan zone model, which defines each zone as a percentage of your FTP — from Zone 1 recovery spins below 55% up to Zone 6 anaerobic efforts above 120%. For the zones to be accurate your FTP needs to be current, so retest every 4–6 weeks — here's how to test your FTP, including protocols, pacing, and turning the zones into structured sessions.