Example result based on the prefilled values.
Max HR
185.00 bpm
Fat Burn
125.00-137.00
Aerobic
137.00-149.00
Threshold
149.00-161.00
VO2 Max
161.00-173.00
Continue your plan
Useful next calculations
When to use this calculator
- Before setting a new health goal or checking whether a plan is realistic.
- When you want to compare different assumptions without tracking them manually.
- When you need a quick baseline before discussing the result with a professional.
- When you are starting a new fitness or diet programme and want an objective starting-point measurement.
- When you want to recheck your numbers after several weeks of change to see whether the metrics are moving in the right direction.
A realistic Ireland planning example
Use these sample inputs as a quick scenario test, then change one variable at a time to compare outcomes.
Age
35
Resting Heart Rate (bpm)
5%
After entering these figures, review max hr, fat burn and aerobic together rather than in isolation — each metric tells a different part of the story. Then rerun the tool with one input adjusted to see which variable has the biggest effect on all three outputs before you settle on a plan.
How to read your results
Max HR
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Fat Burn
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Aerobic
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
Threshold
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
VO2 Max
Use this metric to compare scenarios side by side and understand how changes in the key inputs drive the final outcome. If the figure surprises you, isolate one variable at a time and rerun the calculation to identify which assumption is responsible.
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.
- !Forgetting location-specific taxes, fees, eligibility rules or payroll deductions where they apply.
- !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.
- Use the result to prepare better questions for a lender, provider, adviser or employer rather than treating it as a final answer.
Frequently asked
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