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Heart Rate Zone Calculator — Training Zones from HR
Calculate heart rate training zones from max HR, LTHR or using the Karvonen method.
How We Calculate This
Heart Rate Zone Methods
% of Max HR: Each zone is a percentage range of your maximum heart rate. Simple but less personalised.
LTHR-based: Zones are set relative to your lactate threshold heart rate. Uses Joe Friel's 7-zone cycling model (Z1 <81%, Z2 81–89%, Z3 90–93%, Z4 94–99%, then sub-threshold zones 5a 100–102%, 5b 103–106%, 5c >106% of LTHR), the most popular HR model with serious cyclists. Note: Friel's zones are heart-rate based — Andrew Coggan's separate 7-level system is a power (FTP) model, not a HR model.
Karvonen: Target HR = Resting HR + (Heart Rate Reserve x intensity%). More personalised as it accounts for resting heart rate.
Frequently Asked Questions
If you know your LTHR from a test, use the LTHR method as it is most accurate. If you only know your max HR, the percentage of max HR method works well. Karvonen is useful if you also know your resting HR.
The most reliable way is a supervised max HR test. The "220 minus age" formula is a rough estimate with a standard deviation of 10-12 bpm. A 30-second sprint up a steep hill after a warm-up can approximate it.
Your LTHR is approximately your average heart rate during a 30-minute all-out time trial (take the last 20 minutes average). It corresponds closely to your FTP heart rate.
The Karvonen method uses Heart Rate Reserve (HRR = Max HR - Resting HR) to calculate zones. Target HR = Resting HR + (HRR x intensity%). It accounts for individual fitness via resting HR.
Related Calculators
Power Zone Calculator
Calculate power-based training zones from your FTP.
Threshold Calculator
Find your lactate threshold from heart rate or power data.
TSS Calculator
Calculate Training Stress Score from power and duration.
Training Stress Calculator
Calculate TSS (Training Stress Score) from power, duration, and FTP.
FTP Calculator
Estimate your Functional Threshold Power from test results.
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Last updated: June 2026
All calculations are estimates. Always verify results and consult a professional bike fitter where appropriate.