Skip to content

Heart Rate Zone Calculator

Calculate personalised heart rate training zones using the Karvonen method. Find your fat burn and aerobic zones.

Last reviewed 15 August 2026Reviewed after a methodology change

Your details

Calculator inputs

When to use this calculator

  • Before setting a new health goal or checking whether a plan is realistic.
  • When you want a quick baseline before discussing the result with a professional.
  • When you are starting a fitness or diet programme and want a starting measurement.
  • When you want to recheck the numbers after several weeks of change.

A realistic planning example

Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.

A realistic planning example
InputValue
Age35
Resting Heart Rate (bpm)5%

After entering these figures, review max hr, fat burn and aerobic together rather than in isolation. Then rerun the tool with one input adjusted.

How to read your results

Max HR

The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.

Fat Burn

The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.

Aerobic

The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.

Threshold

The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.

VO2 Max

The figure produced by this output for the inputs you entered. Change one variable at a time if you want to see what drives it.

Method & assumptionsAuthoritative sources

Heart rate zone calculators estimate your training zones based on your maximum heart rate (MHR), which is most commonly approximated using the formula 220 minus your age. More accurate results can be achieved using the Karvonen formula, which incorporates your resting heart rate to calculate Heart Rate Reserve and produces personalised zone thresholds. Each zone corresponds to a different physiological effect and training stimulus. It is worth understanding that MHR formulas are population averages — individual maximum heart rates can vary by 10 or more beats per minute from what the formula predicts. Wearable devices using optical heart rate sensors also introduce measurement error. For accurate zone calibration, a supervised exercise test with a sports physiologist is the gold standard approach.

Common mistakes

  • !Using an assumption that is not supported by a current local quote, bill, statement or official source.
  • !Treating a generic estimate as a lender, provider, payroll or tax authority decision.
  • !Mixing monthly and annual inputs without converting them consistently.
  • !Testing only one scenario instead of checking how a cautious assumption changes the result.

What to do next

  • Run a second scenario with a cautious assumption so you can see the downside clearly.
  • Compare the result with the related calculators below before making a decision.
  • Check current local rules, eligibility and provider terms before applying or committing money.
  • Keep a record of the assumptions so you can update the estimate when a quote, bill or pay figure changes.

Keep exploring

Browse all tools

Frequently asked

The 220-minus-age formula gives a rough estimate. A more accurate method is a maximal effort test (e.g. running uphill to exhaustion) under professional supervision.

Use arrow keys to navigate items, Enter or Space to expand/collapse.