Functional Threshold Power (FTP) is the highest average power in watts you can sustain for approximately one hour — the cornerstone metric for structured cycling training. Every training zone, interval target, and progressive overload recommendation is anchored to your FTP. This estimator converts your field test result into an accurate FTP estimate and shows your watts per kilogram classification alongside a preview of your Coggan training zones.
Test Details
How to Use the Cycling FTP Estimator
Your cycling FTP is the single most important number for structured training. This FTP estimator converts any of four standard field test results into an accurate FTP estimate, then shows your watts per kilogram classification and a full Coggan zone preview so you can start training immediately.
Step 1: Choose Your Test Type
Select the test you performed. The 20-minute all-out test is the gold standard — ride as hard as you possibly can for 20 minutes on a flat road or indoor trainer, then multiply your average power by 0.95. The ramp test increases power every minute until you fail; your FTP is 75% of your best 1-minute power. The 8-minute test uses a single maximal effort and a 0.90 factor. The 2×8-minute test uses two efforts with rest between them for a slightly more reliable estimate.
Step 2: Enter Your Test Power
Enter the average power you held during the test in watts. Use your power meter or smart trainer's recorded average — not normalised power, which would overestimate FTP. If you did a 2×8-minute test, enter the average of both efforts. The calculator applies the correct factor for your chosen test type automatically.
Step 3: Enter Your Body Weight
Body weight is used to calculate your watts per kilogram ratio (w/kg), which is the best way to compare cycling fitness across riders of different sizes. Switch between kg and lbs using the unit toggle at the top of the page. Your weight does not affect the FTP calculation itself — only the w/kg metric and classification.
Step 4: Read Your Results
The calculator shows your estimated FTP in watts, your watts per kilogram ratio, and your performance classification based on widely referenced benchmarks. A visualisation shows where you sit on the spectrum from untrained to professional. Below that, a full Coggan zone table gives you power targets for every training session from recovery rides (Zone 1) to VO2max intervals (Zone 5) and anaerobic work (Zone 6).
How Often to Retest
Retest your FTP every 6-8 weeks, always after a rest week when you are fully recovered. As your fitness improves, your old zones become too easy and training loses effectiveness. Many athletes see 10-20 watt improvements in their first season of structured training. Track your FTP history alongside training load to confirm that your programme is producing adaptation.
Frequently Asked Questions
Is this FTP estimator free?
Yes, completely free with no signup required. All calculations happen locally in your browser and no data is ever transmitted to a server.
Is my data safe and private?
Yes, all calculations happen entirely in your browser. Your power data and weight are never sent to any server or stored after you close the page.
What is FTP and why does it matter for cycling?
Functional Threshold Power (FTP) is the highest average power in watts you can sustain for approximately one hour. It is the gold standard metric for setting cycling training zones, prescribing interval intensities, and tracking fitness progress across a season. All major training platforms — Zwift, TrainerRoad, Wahoo — use FTP as the foundation of their structured training plans.
What is the difference between the 20-minute and ramp tests?
The 20-minute all-out test gives the most accurate estimate: you ride as hard as possible for 20 minutes and multiply average power by 0.95. The ramp test (1-minute increments until failure) is shorter and less mentally demanding — FTP is estimated at 75% of your best 1-minute power. The ramp test may slightly overestimate FTP for athletes with a strong aerobic base.
How is the 8-minute test different from the 20-minute test?
For the 8-minute test, you do a single all-out 8-minute effort and multiply average power by 0.90. The 2×8-minute variant uses two 8-minute efforts with 10 minutes rest between them and averages the two powers before applying the 0.90 factor. The 8-minute protocols suit athletes who find sustained 20-minute efforts too taxing, but the shorter duration introduces more anaerobic contribution and can slightly inflate the estimate.
What is a good watts per kg ratio for cycling?
For amateur cyclists, 2-3 w/kg is a solid recreational level. Cat 4/5 racers typically sit at 3-3.5 w/kg. Competitive Cat 3 riders reach 3.5-4 w/kg. Strong Cat 1/2 riders are 4-5 w/kg. Professional Tour riders maintain 5.5-6.5 w/kg, with climbers reaching 6+ w/kg at peak form. The classifications shown by this calculator are based on widely referenced benchmarks from TrainingPeaks and the Coggan/Allen framework.
How often should I retest my FTP?
Most coaches recommend retesting every 6 to 8 weeks. As fitness improves, FTP rises and your old zones become too easy, making structured training sessions less effective. Retest after a recovery week when you are well rested, not during a heavy training block.
Can I estimate FTP without a power meter?
A power meter or smart trainer is needed to measure watts directly. However, if you ride on a consistent flat course, you can use average speed as a rough proxy after a 20-minute all-out effort and enter it into a cycling speed-to-power calculator. For accurate training zones and long-term tracking, a power meter or smart trainer is strongly recommended.