Target Heart Rate Calculator
Find your maximum heart rate and target training zones using the Karvonen (heart-rate reserve) method.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
This tool provides general educational estimates only and is not medical advice. It does not diagnose, treat, or replace guidance from a qualified healthcare provider. Consult a doctor for decisions about your health.
About the Target Heart Rate Calculator
The target heart rate calculator gives your training zones using the Karvonen (heart-rate reserve) method. It estimates your maximum heart rate as 220 minus your age, subtracts your resting heart rate to get your heart-rate reserve, and then adds a percentage of that reserve back onto your resting rate for each zone. Because it uses your resting heart rate, it adjusts for fitness better than a simple percentage of maximum heart rate. The zones range from an easy warm-up effort to near-maximal intervals.
How to use it
- 1Enter your age.
- 2Measure your resting heart rate on waking, before getting up, and enter it.
- 3Press Calculate to see your estimated maximum heart rate and each training zone in beats per minute.
Worked example
a 30-year-old with a resting heart rate of 65 bpm has an estimated maximum of 190 bpm and a reserve of 125 bpm. 60% intensity is 65 + 0.6 × 125 = 140 bpm, and 80% intensity is 165 bpm.
How it works
Karvonen formula
Target = resting HR + intensity × (max HR − resting HR), where max HR ≈ 220 − age.
Who it is for
Runners, cyclists and fitness enthusiasts who train with a heart-rate monitor.
Why it helps
Zones keep easy days easy and hard days hard, which is how most endurance training is structured.
Common use cases
- Setting heart-rate alerts on a sports watch
- Keeping long runs in an aerobic zone
- Planning interval intensity
Common mistakes to avoid
- Treating 220 − age as your measured maximum; individual maximums can differ by 10–20 bpm.
- Measuring resting heart rate after coffee or activity.
Frequently asked questions
A:The difference between your maximum and resting heart rate; Karvonen uses it for more personal zones.
A:The 60–70% zone is often called fat-burning, but higher zones burn more total calories.
Reviewed for accuracy · Last updated October 7, 2026
Formulas follow recognised clinical references — including WHO BMI classifications, the Mifflin-St Jeor equation, and Naegele’s rule — and are periodically checked against published reference values.
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
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