Heart Rate Reserve Calculator
Calculate heart rate reserve zones.
About Heart Rate Reserve Calculator
Heart-rate zones for Heart Rate Reserve use the Karvonen formula, adding a fraction of the heart-rate reserve to the resting rate to set a training target. Reserve-based targets adapt to fitness, so two people of the same age can train in very different zones.
Formula
Heart Rate Reserve
Target HR = resting + (max - resting) x intensity%
- Karvonen
- Reserve method accounts for the resting rate
Worked example
With the default values below, Heart Rate Reserve Calculator returns Maximum Heart Rate of 190. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Ageminimum 0 years
- 30 years
- Resting heart rateminimum 0 bpm
- 62 bpm
- Target intensityaccepts 0–100 %
- 70 %
Results
- Maximum Heart Rate
- 190 bpm
- Target Heart Rate
- 152 bpm
- Heart Rate Reserve
- 128 bpm
Step by step
- 1Values used
- 2Heart Rate Reserve
- 3Maximum Heart Rate= 190 bpm
- 4Target Heart Rate= 152 bpm
- 5Heart Rate Reserve= 128 bpm
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to whole numbers, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- These are educational and reference calculations only. They are not a diagnosis, not a substitute for measurement or laboratory testing, and must not be used to start, stop, time or change any medication or treatment. Reference thresholds differ between national guidelines and do not account for your individual clinical context. Discuss any result that concerns you with a qualified healthcare professional, and seek urgent medical attention for acute symptoms rather than relying on a calculator.
- This is an estimate for general information and not professional medical advice. See the full disclaimer for the limits that apply to this kind of calculator.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
These are educational and reference calculations only. They are not a diagnosis, not a substitute for measurement or laboratory testing, and must not be used to start, stop, time or change any medication or treatment. Reference thresholds differ between national guidelines and do not account for your individual clinical context. Discuss any result that concerns you with a qualified healthcare professional, and seek urgent medical attention for acute symptoms rather than relying on a calculator.
Frequently Asked Questions
How is Heart Rate Reserve calculated?
Target HR = resting + (max - resting) x intensity% Heart-rate zones for Heart Rate Reserve use the Karvonen formula, adding a fraction of the heart-rate reserve to the resting rate to set a training target.
Why does Heart Rate Reserve matter?
Reserve-based targets adapt to fitness, so two people of the same age can train in very different zones.
What values do I need to enter?
This calculator takes 3 inputs: Age, Resting heart rate, Target intensity. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.