FTP Calculator

FTP is the single most useful number in cycling. It is the foundation your power zones are built on, the figure that makes training stress comparable week to week, and the one most riders either guess at or leave months out of date. The calculator above turns a short test into a real number plus the seven zones you actually train in.

What FTP is

Functional Threshold Power is the highest average power you could hold for about an hour. You do not have to ride for an hour to find it. A shorter, harder test gives you a power figure, and a simple percentage converts that into your FTP.

• 20-minute test: ride as hard as you can hold for 20 minutes. FTP is 95% of that average power.
• 8-minute test: a shorter option for riders who struggle to pace 20 minutes. FTP is about 90% of the average.
• Ramp test: ride increasing power until you cannot continue. FTP is roughly 75% of your best one-minute power.

Pick the one you can pace honestly. A test you blow up halfway through gives you a number that is no use.

Reading your zones

Once you have FTP, every zone falls out of it as a percentage. The calculator gives you the standard seven-zone model: recovery, endurance, tempo, threshold, VO2max, anaerobic, and the sprint efforts above. Most of your weekly volume should sit in endurance, with threshold and VO2max work added in measured doses.

Power to weight matters too if you climb or race. Add your body weight above and you get watts per kilogram, the number that actually predicts how you go uphill.

How often to retest

FTP moves as you train. Test every four to six weeks during a focused block, not every week. Testing too often just adds fatigue and noise. If your threshold sessions are suddenly feeling easy, that is your cue to retest and nudge the zones up.

A word of caution: a wrong FTP poisons everything downstream. Set it too high and every session sits above where it should, you accumulate fatigue you cannot absorb, and progress stalls. Set it from an honest test, not from ego.

Your FTP is also the cleanest input you can hand a coach. For how power, normalized power, and intensity tie together across a ride, read the normalized power guide.