Heart Rate Zone Calculator
Calculate your five heart rate training zones with the Karvonen (heart rate reserve) method for accurate, personalised intensity targets.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
This tool provides general sports and fitness estimates for educational purposes only. It is not medical advice — consult a physician before starting or intensifying training, especially if you have a cardiovascular condition.
About the Heart Rate Zone Calculator
The heart rate zone calculator gives five training zones using the Karvonen formula: zone heart rate = resting HR + zone % × (max HR − resting HR). Including resting heart rate makes the zones fit your fitness level better than a simple percentage of maximum.
How to use it
- 1Enter your age.
- 2Enter your resting heart rate.
- 3Press Calculate to see each zone in beats per minute.
Worked example
a 40-year-old with a resting heart rate of 65 (maximum 180) has a 60–70% zone of 134–146 bpm.
How it works
Formula
Zone HR = Resting HR + Zone% × (Max HR − Resting HR), with Max HR = 220 − Age.
Common use cases
- Structuring endurance training
- Programming a sports watch
- Balancing easy and hard days
Frequently asked questions
A:It factors in resting heart rate, so zones reflect your individual working range rather than a generic percentage of max.
A:The 80/20 rule places about 80% of weekly volume in zones 1–2 and 20% in zones 4–5.
A:Zone 2 builds mitochondrial density, capillarisation, and fat oxidation — the aerobic base for all endurance work.
A:Yes — cycling and swimming heart rates typically run 5–15 bpm lower than running at the same effort.
A:Recalculate every 8–12 weeks or after a noticeable change in fitness or resting heart rate.
Reviewed for accuracy · Last updated October 7, 2026
Formulas follow published sports-science literature and official league definitions (Karvonen heart rate reserve, Cooper and Bruce protocols, MET compendium values, and standard baseball, cricket, and basketball statistics).
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources