FTP Calculator

FTP stands for functional threshold power — the highest average power, in watts, that you can sustain for roughly an hour. It is the single most useful number in structured cycling training because it anchors your power zones: once you know your FTP, every workout intensity can be expressed as a percentage of it.

FTP sits near the boundary between efforts you can hold for a long time and efforts that force you to stop within minutes. Train just below it and you can accumulate a lot of work; push above it and fatigue arrives quickly. That is why coaches build training around it rather than around raw top-end power.

How FTP is calculated

The most common field estimate comes from a 20-minute test. You ride a maximal, well-paced 20-minute effort, take the average power, and multiply by 0.95:

The 5% reduction exists because you can hold more power for 20 minutes than for a full hour. Subtracting it converts your 20-minute number into a practical estimate of true one-hour power. Other protocols exist — ramp tests, 8-minute tests, and longer efforts — and they can produce slightly different numbers. For a full walkthrough of the ramp test versus the 20-minute test, and which number to actually train with, see our guide — but treat any single result as a well-grounded estimate rather than a fixed truth.

How to perform a 20-minute FTP test

A clean test is mostly about pacing and freshness. A workable protocol:

• Arrive rested. Test on fresh legs — ideally after an easy day or rest day, not on the back of a hard block.
• Warm up properly. 15–20 minutes of easy riding with two or three short, sharp efforts to open up the legs.
• Optionally clear the legs. Many protocols include a 5-minute hard effort followed by easy spinning before the main test, so your first minutes are not artificially fresh.
• Ride the 20 minutes evenly. Settle into a hard but sustainable pace you could just hold to the end. Resist going out too hard — fading badly in the last five minutes is the most common way to ruin the result.
• Take the average and multiply by 0.95. Enter that 20-minute average in the calculator above to get your FTP and zones.

What is a good FTP?

To see where your number lands — from novice to elite — read what is a good FTP. But raw FTP in watts is only half the story, because a heavier rider naturally produces more watts. For comparing riders, what matters is power-to-weight — watts per kilogram — which you can work out with the W/kg calculator and check against the W/kg chart. A 250 W FTP means something very different for a 60 kg climber than for a 90 kg rider.

More useful than chasing an absolute number is watching your own FTP trend over months of consistent training. For most amateurs, steady improvement and good fatigue management matter far more than hitting any particular benchmark.

What to do with the number

An FTP is only useful once it is doing a job. Three next steps, depending on what you want to know:

• Set your training zones. The cycling power zone calculator turns your FTP into the full seven-zone table in watts, with the purpose of each zone. This is the step that actually changes your riding.
• Then mostly leave it alone. Every 8 to 12 weeks is enough for most riders — how often to test your FTP covers the signals that a retest is genuinely warranted.
• See how it compares. What is a good FTP covers what each wattage means and why body weight changes the answer.
• Get the fair comparison. Divide it by your body weight with the W/kg calculator — that is the figure riders of different sizes actually compare.