Cycling FTP Calculator
Created by: James Porter
Last updated:
Estimate functional threshold power from the most common cycling tests, then turn that result into watts per kilogram and a full Coggan power-zone profile for training.
Cycling FTP Calculator
CyclingEstimate FTP, W/kg, and your full cycling power zones from the most common field tests.
What is a Cycling FTP Calculator?
A cycling FTP calculator estimates your Functional Threshold Power and maps it into training zones. FTP is the anchor used in most modern cycling plans because it gives a practical reference for endurance, tempo, threshold, VO2 max, and anaerobic workouts.
Many riders do not perform a true 60-minute test regularly, so field tests like a 20-minute effort or ramp test are commonly used. This calculator converts those tests into an FTP estimate and then builds all seven Coggan zones from it.
It also calculates watts per kilogram, which is one of the most useful ways to compare cycling fitness across body sizes and terrain demands.
How It Works
The calculator applies a standard conversion factor to your chosen test type: about 95% of 20-minute power, 90% of 8-minute power, or 75% of a ramp-test peak minute. That estimated FTP becomes the base for every zone.
Each Coggan zone is defined as a percentage of FTP. Recovery work sits well below threshold, while VO2 max and anaerobic work rise well above it.
Watts per kilogram is then calculated by dividing FTP by body weight in kilograms, which helps classify your overall cycling performance level.
Example Scenarios
A rider averaging 260 watts for 20 minutes would estimate FTP at about 247 watts. If that rider weighs 70 kg, FTP is about 3.5 W/kg.
That profile typically lands in a solid trained amateur range and supports useful zone-based structure for endurance, sweet spot, and VO2 work.
The same absolute FTP at a heavier body weight may still be strong on flat terrain, but W/kg helps reveal why climbing performance can feel different.
Applications
- Estimate FTP from common field-test formats
- Build all seven Coggan cycling power zones
- Compare your watts per kilogram to broad performance categories
- Set more precise workouts for endurance, threshold, and VO2 training
- Track progress over time with the same testing method
Practical Tips
- Use the same test type each time so comparisons stay meaningful.
- Retest after a focused training block instead of every few days.
- Indoor and outdoor test results may differ because cooling and pacing differ.
- FTP is a guide for training, not a complete summary of all cycling abilities.
- Recalculate zones if body weight or sustained power changes meaningfully.
FAQ
What is FTP in cycling?
Functional Threshold Power is the highest power output you can roughly sustain for about one hour. It is commonly used as the anchor for cycling training zones.
Why does a 20-minute test use 95%?
A 20-minute effort is shorter than a true one-hour threshold effort, so the common field-test convention is to estimate FTP as about 95% of the 20-minute average power.
What does watts per kilogram tell me?
W/kg normalizes FTP to body size, which makes it more useful for comparing cycling fitness across riders, especially on climbs.
Are Coggan zones still useful?
Yes. They remain one of the most common practical frameworks for structuring endurance rides, tempo work, threshold blocks, VO2 sessions, and anaerobic intervals.
How often should I recalculate FTP?
Most riders retest every 4-8 weeks during focused training blocks or after a noticeable improvement in fitness.
Sources
- Coggan AR, Allen H. Training and Racing with a Power Meter.
- Hunter Allen and Andrew Coggan FTP field-test conventions.
- Common performance benchmarking conventions for cycling W/kg categories.