Heart Rate Zones Calculator
Exercise intensity planning
Estimate maximum heart rate and training zones
Result
Calculation summary
Enter values to see the result
Zone preview
Five-zone heart rate map
How to use this calculator
- 1Enter age and choose an age-based maximum-heart-rate estimate or a measured custom maximum.
- 2Choose percentage of maximum heart rate or heart rate reserve; the reserve method also uses resting heart rate.
- 3Review the five planning zones plus the moderate and vigorous reference ranges.
Formula
HRR target = resting HR + intensity × (maximum HR − resting HR)
The alternative maximum-heart-rate method multiplies estimated or custom maximum heart rate directly by each intensity percentage.
Calculation steps
- Estimate maximum heart rate with 208 − 0.7 × age or 220 − age, unless a custom maximum is supplied.
- Calculate heart rate reserve when that method is selected.
- Apply each percentage boundary and round the displayed beats per minute to whole numbers.
Worked example
At age 30 with a resting rate of 60 bpm, the 208 − 0.7 × age estimate gives 187 bpm. The heart-rate-reserve method places the 50% to 70% range at about 124 to 149 bpm.
Assumptions
- Age-predicted maximum heart rate is a population estimate and can differ materially from an individual measured maximum.
- The five equal percentage bands are a general planning convention; device, coach, laboratory, and sport-specific zone definitions can differ.
- The American Heart Association describes moderate intensity as about 50% to 70% and vigorous intensity as about 70% to 85%.
- Medication, health conditions, temperature, hydration, and measurement error can affect heart rate.
Sources
Frequently asked questions
Which zone method should I choose?
Use percentage of maximum heart rate for a simple estimate. Heart rate reserve also incorporates resting heart rate and therefore requires a reliable resting measurement.
Is 220 minus age exact?
No. It is a broad age-based estimate. The calculator also offers 208 − 0.7 × age and lets you enter a professionally measured maximum.
Why do zones overlap at their boundaries?
A boundary such as 70% is the shared transition between adjacent bands. Heart rate also changes continuously, so a one-beat boundary should not be treated as absolute.
Can this calculator prescribe a safe workout?
No. It is educational arithmetic, not medical screening or an exercise prescription. Heart conditions, symptoms, and medicines require individualized professional guidance.