Power vs Heart Rate Zone Comparison
Compare one cycling effort with your FTP and threshold heart rate on two separate zone scales.
Compare the power you produce with your heart's response. Use values from the same ride or interval.
Your cycling thresholds
The effort to compare
Use a steady lap when possible. Whole-ride averages can hide surges and coasting. Readings are rounded to whole watts and bpm.
No account needed. Calculated in your browser.
Power zone
205 W · 78.8% FTP
Heart-rate zone
154 bpm · 89.5% LTHR
Same named band
Same band on two different scales. This is a comparison, not a fitness or recovery score.
Very easy spinning, cooldowns, and recovery rides.
Aerobic base work and long steady endurance rides.
Steady pressure, climbs, and controlled moderate work.
Hard sustainable intervals and time-trial style work.
Higher-power work, above-threshold efforts, and surges. This simplified band pools intensities that fuller models separate.
For short intervals, surges, and pacing exact output, power reacts immediately while heart rate catches up later.
For endurance rides, heat, fatigue, drift, and recovery checks, heart rate shows how costly the power is today.
This simplified five-band comparison uses power limits at 55%, 75%, 90%, and 105% of FTP; heart-rate limits at 81%, 88%, 93%, and 99% of cycling LTHR. It combines higher intensities into one band. Band numbers from different metrics are not physiological equivalents.
For fuller systems and threshold methods, see Coggan’s power levels and Friel’s heart-rate zones.
From numbers to understanding
Power measures output, while heart rate reflects your response. Compare values from the same steady lap or interval using this simplified five-band model, then review the conditions, sensors, and thresholds behind the numbers.
Enter your current cycling FTP and cycling threshold heart rate.
Enter power and heart rate from the same ride section, preferably a steady lap.
Compare each reading’s position on its own scale. Matching zone numbers do not establish matching physiological intensity.
Review interval length, heat, hydration, fatigue, perceived effort, sensor quality, and whether your thresholds are current.
Power responds immediately and is useful for pacing short intervals. Heart rate adds context during steady efforts. A difference can reflect timing, conditions, sensor error, outdated thresholds, or this simplified model; the tool cannot determine the cause.
Yes. FTP and threshold heart rate should come from cycling when possible. Running heart-rate zones may not match bike-specific responses.
No. It is a practical comparison tool. Use coach-tested, lab-tested, or repeatable field-test anchors when accuracy matters.
Explore the ideas behind the numbers.
Keep exploring
Zone Training Log
A privacy-first training log for iOS and Android. Free to start. Yours to make personal.
