How to use the Heart Rate Zone Calculator
Start by choosing the method that matches the heart-rate value you have. Enter the requested values, check the zone percentages, and select Calculate zones to see the five ranges, the formula, and the rounded whole-bpm boundaries.
- Select % of Max HR, Heart-rate reserve (Karvonen), or % of threshold HR (LTHR).
- Choose a Max HR source when the selected method uses Max HR.
- Enter the fields shown, such as Age (years), Resting heart rate (bpm), or Lactate threshold heart rate - LTHR (bpm).
- Review the percentages, then select Calculate zones.
Choose the heart rate zone method
% of Max HR multiplies Max HR by each zone percentage. Heart-rate reserve (Karvonen) applies the percentage to HRR and adds Resting heart rate (bpm). % of threshold HR (LTHR) multiplies the LTHR you enter by each percentage.
- Max HR source includes Estimate: 220 − age, Estimate: 208 − (0.7 × age), and Manual entry (measured Max HR).
- Heart-rate reserve (Karvonen) asks for Resting heart rate (bpm) as well as Max HR.
- % of threshold HR (LTHR) asks for Lactate threshold heart rate - LTHR (bpm). The calculator does not estimate it.
Age (years): 35
Max HR source: Estimate: 220 − age
Zone 2: 60% - 70%
Result: 111 - 130 bpmEdit heart rate zone percentages
The table starts with five rows: Very light / recovery, Light / endurance, Moderate / aerobic, Hard / threshold, and Maximum / anaerobic. Change either percentage before selecting Calculate zones. Reset percentages to defaults restores those starting values.
Enter whole numbers in the method fields. Age (years) accepts 1 to 120, Measured Max HR (bpm) accepts 60 to 240, Resting heart rate (bpm) accepts 20 to 150, and Lactate threshold heart rate - LTHR (bpm) accepts 60 to 240. With Heart-rate reserve (Karvonen), Max HR must be greater than resting heart rate.
Each percentage must be zero or higher, and its upper value must be greater than its lower value. The five zones can have gaps or overlap. Reset clears the entered fields, restores the default Max HR source and percentages, hides the result, and leaves the selected method unchanged.
Read and export the heart rate zone results
The result panel lists the selected method, its formula, five percentage ranges, and five heart-rate ranges rounded to whole bpm values. Heart-rate reserve (Karvonen) also lists Max HR, Resting HR, and HRR.
After calculating, select Copy result to copy the text or Download zone table (.txt) to save a plain-text file containing the method, formula, zone rows, and disclaimer. The page scripts do not send the values you enter with fetch, XMLHttpRequest, sendBeacon, or a form post.
Use a measured value when you have one
Choose Manual entry (measured Max HR) when you already have a measured Max HR. For a threshold-based calculation, enter the measured or tested Lactate threshold heart rate - LTHR (bpm). The Heart-rate reserve (Karvonen) method uses Resting heart rate (bpm) to calculate HRR before it creates each range.
When another sports calculator fits better
This calculator converts Max HR, HRR, or LTHR into training zones. The Sports Calculators category contains the other sports calculations on the site.
Use the Cycling Calculator for cycling speed, distance, time, pace, or estimated energy use. Use the Race Equivalent Calculator for an equivalent time at another distance based on a completed race or hard effort. Use the Race Finish Time Calculator when you have a distance and target pace or speed.
Frequently asked questions
Which method should I use to calculate heart rate zones?
The calculator supports % of Max HR, Heart-rate reserve (Karvonen), and % of threshold HR (LTHR). Choose the method that matches the value you have, since the first needs Max HR, the second also needs resting heart rate, and the third needs LTHR.
How do I calculate Karvonen heart rate zones?
Select Heart-rate reserve (Karvonen), provide Max HR and Resting heart rate (bpm), then select Calculate zones. The calculation uses HRR = Max HR - Resting HR and Zone HR = (HRR x zone %) + Resting HR.
Can I use LTHR for lactate threshold heart rate zones?
Yes. Select % of threshold HR (LTHR) and enter a measured or tested Lactate threshold heart rate - LTHR (bpm); the calculator does not measure or estimate that value.
Can I change the heart rate zone boundaries?
Yes. Edit each lower and upper percentage before selecting Calculate zones. The calculator accepts non-negative values with an upper percentage greater than the lower percentage, including ranges with gaps or overlap.