Cycling Power Zone Calculator
Enter a 20-minute or ramp test to get your FTP, power zones, W/kg, session targets and predicted bike splits.
Your power test
From a power meter or smart trainer, ridden flat out.
FTP = 95% of your 20-minute average
Used for speed and race-time estimates
| Triathlon bike leg | Target power | Time |
|---|---|---|
| Sprint (20 km) | 202–226 W85–95% FTP | 31:19–32:41 |
| Olympic (40 km) | 190–214 W80–90% FTP | 1:03:57–1:06:54 |
| Ironman 70.3 (90 km) | 178–195 W75–82% FTP | 2:29:05–2:34:18 |
| Ironman (180 km) | 166–181 W70–76% FTP | 5:07:02–5:16:59 |
| Time trial | Average power | Time |
|---|---|---|
| 10 mile TT | 248 W | 24:20 |
| 25 mile TT | 237 W | 1:01:50 |
Estimates for a flat, calm course with no drafting, riding tt / triathlon bike at 84 kg all-in. Hills, wind, corners and rough roads will make real times slower. Triathlon targets leave enough in your legs to run well afterwards.
| Zone | Power |
|---|---|
Easy spinning, recovery rides. | Up to 131 W< 55% FTP |
All-day pace. The bulk of long rides. | 132–178 W55–75% FTP |
Brisk, steady effort. Long-course race intensity. | 179–214 W75–90% FTP |
Around FTP. 2 × 20 min, 3 × 12 min. | 215–249 W90–105% FTP |
3-8 min reps that lift your aerobic ceiling. | 250–285 W105–120% FTP |
30 s - 3 min efforts. Hard and short. | 286–356 W120–150% FTP |
Maximal sprints under 30 s. | 357 W +> 150% FTP |
(88–94% FTP, ) sits across the top of tempo and the bottom of threshold, a time-efficient way to lift FTP.
| Session | Target |
|---|---|
| Endurance ride2–4 hours, steady | 132–178 W |
| Sweet spot3 × 15 min, 5 min easy between | 209–223 W |
| Threshold2 × 20 min, 5 min easy between | 226–238 W |
| VO₂ max5 × 4 min, 4 min easy between | 252–273 W |
| Anaerobic6 × 1 min, 4 min easy between | 309–356 W |
Your triathlon thresholds
Saved on this deviceHow the cycling power calculator works
Your FTP comes from your test: 95% of your 20-minute average (the British Cycling and Allen & Coggan protocol), or 75% of your best minute in a ramp test. The seven training zones are Dr Andrew Coggan's power levels, the same ones used by TrainingPeaks and WKO.
Speeds come from the physics of riding on a flat road with no wind: the power you put through the pedals balances air resistance, which depends on your riding position, and rolling resistance, which depends on the total weight of you and your bike. Changing position shows how much free speed an aero setup is worth.
For time trials, the power you can sustain falls as the effort gets longer, so a 10 mile TT is ridden a little above FTP and a 25 mile TT close to it. Triathlon bike targets are lower still, because you have to run afterwards.
Common questions
What is FTP?
Functional threshold power (FTP) is roughly the highest average power you could hold for about an hour. Training zones are set as a percentage of it, so a good FTP estimate makes every session more precise.
How do I do a 20-minute FTP test?
Warm up for 15 to 20 minutes, including a few short hard efforts, then ride 20 minutes as hard as you can evenly sustain. Your FTP is 95% of the average power. A turbo trainer or a steady, uninterrupted road works best.
What should I aim for in a triathlon bike leg?
The longer the race, the lower the percentage of FTP, because you still have to run. As a guide: 85-95% for a sprint, 80-90% for an Olympic, 75-82% for a 70.3 and 70-76% for an Ironman. Newer athletes and long-course first-timers should start at the lower end.
Why are my real bike splits slower than the prediction?
The predictions assume a flat, calm course, steady power and no braking. Hills, wind, corners, road surface, traffic and your position on the day all add time. They are most useful for comparing positions and power targets.