How to Use the Cycling FTP Power Zone Calculator
The most precise way to manage intensity in cycling training isn't heart rate — it's power (watts). FTP (Functional Threshold Power) is roughly the maximum average power you can sustain for about an hour, and this calculator takes just your FTP and applies Dr. Andrew Coggan's classic 7-zone model to compute the wattage range for every zone, from Z1 active recovery through Z7 neuromuscular power.
The Z2 endurance zone is where you build your long, aerobic base; the Z4 threshold zone drives interval work that raises your FTP itself; and the higher-intensity Z5-Z7 zones cover the short, explosive efforts needed for sprints and hill repeats. Knowing the exact wattage range for the zone that matches your training goal lets you dial in intensity precisely on a smart trainer or with a power meter.
FTP shifts with your fitness and training load, so it's worth retesting every 4-6 weeks and updating your zones. If you've just come off a block of heavy indoor training, your FTP has likely climbed — check the FAQ below for how to retest, then recalculate with the new number.
Frequently Asked Questions
The most common method is a 20-minute all-out time trial, then taking 95% of your average power as your FTP. A smart trainer or power meter gives you a fairly accurate result with this test.
Heart rate lags behind effort and shifts with caffeine, sleep, and heat, while power (watts) measures the actual force on the pedals instantly, reflecting sudden changes in intensity far more precisely.