Heart Rate Zone Calculator

Updated Sep 2026 Used 0 times

Choose the maximum-HR sourcePrefer a relevant measured value when available.

Maximum heart-rate source

Measured maximum is preferred when obtained safely and appropriately.

Age

Used only for the Tanaka age estimate.

Measured maximum heart rate

Enter the highest appropriately measured heart rate.

Choose the zone methodEnter resting heart rate for HRR and select the calculation convention.

Resting heart rate

Use a calm resting measurement taken consistently.

Zone method

HRR adds resting heart rate after applying each percentage to the reserve.

Guest calculations stay on this device. Signed-in results sync privately.

Your result

Five heart-rate zones

Enter your values, then calculate to see a verified result.

Inputs usedReview the information used for this result.

Full calculation and sourcesOpen Full calculation and sources to audit the inputs, formula sequence, assumptions, and source scope.

Versioned calculationFormula v1.0.0

Two methods

Compare HRR with percent maximum.

Measured first

Use measured maximum when appropriate.

All bands visible

No hidden device defaults.

Choose max HRMeasured or explicit age estimate.185 bpm

Enter rest HRNeeded for HRR.55 bpm

Match the methodCompare with your device or coach.HRR five-band convention

Interpretation

HRR accounts for resting heart rate.

Measured maximum is more individual.

Zone labels are not universal thresholds.

Use this result

Compare the two methodsSee why HRR and percent-max produce different boundaries.Match your zone systemCheck device, coach, threshold, and medication limitations.

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Public verification recordFormula v1.0.0

Review scope: Tanaka Age Estimation, Measured-HR Path, HRR And Percent-max Formulas, Whole-bpm Rounding, And Inconsistent-input Rejection.
Review team: CalculatorGeek Expert Review Team
Verified: 2026-09-27
Next source review: 2027-03-27
Automated fixtures: 5 cases

Review method

Recompute every 10-point boundary independently across both methods and verify measured and age-estimated maximum paths.

Known limitations

Age equations predict a population average and can miss an individual maximum.
Five-zone labels are not universal and do not equal measured lactate or ventilatory thresholds.
Medication, illness, temperature, dehydration, altitude, fatigue, and sensor error can alter heart rate.
The tool does not diagnose a condition or establish exercise safety.
Use clinician guidance when symptoms, cardiovascular risk, or medication effects are relevant.

Primary sources

Latest update

2026-09-27 · Added source-backed endurance calculation, premium result detail, public fixtures, and unified contextual navigation.

Published calculation checks

Case	Inputs	Expected result
Measured HRR zones	max_hr_source=measured, age_years=35 years, measured_max_hr=185 bpm, resting_hr=55 bpm, zone_method=hrr	heart_rate_reserve=130, zone_2_low=133, zone_2_high=146
Measured percent max	max_hr_source=measured, age_years=35 years, measured_max_hr=200 bpm, resting_hr=60 bpm, zone_method=max	zone_2_low=120, zone_2_high=140
Tanaka age 40	max_hr_source=age, age_years=40 years, measured_max_hr=185 bpm, resting_hr=60 bpm, zone_method=hrr	estimated_or_measured_max_hr=180, heart_rate_reserve=120
Older adult estimate	max_hr_source=age, age_years=70 years, measured_max_hr=170 bpm, resting_hr=60 bpm, zone_method=max	estimated_or_measured_max_hr=159, zone_2_low=95, zone_2_high=111

On this page

Direct answer

The heart rate zone calculator builds five visible bands from either measured maximum heart rate or the Tanaka age estimate, using heart-rate reserve or percentage of maximum.

Heart-rate reserve accounts for resting heart rate; percentage of maximum does not. The five 10-percentage-point zones are a planning convention, not laboratory lactate or ventilatory thresholds.

Estimate a recent field-test fitness signal with the VO2 Max Calculator, then convert a goal into checkpoint pacing with the Running Race Planner.

How to use the calculator

Choose a measured maximum or the age estimate.
Enter a representative resting heart rate.
Choose HRR or percentage of maximum.
Compare the five table rows with your training system.
Update the inputs when better measured data become available.

Inputs, outputs, and result meaning

Inputs

Maximum heart-rate source: Measured maximum is preferred when obtained safely and appropriately.
Age: Used only for the Tanaka age estimate.
Measured maximum heart rate: Enter the highest appropriately measured heart rate.
Resting heart rate: Use a calm resting measurement taken consistently.
Zone method: HRR adds resting heart rate after applying each percentage to the reserve.

Outputs

Maximum heart rate used: Measured maximum or the explicit Tanaka estimate.
Heart-rate reserve: Maximum minus resting heart rate.
Zone 2 lower bound: Lower edge of the 60-70% planning band.
Zone 2 upper bound: Upper edge of the 60-70% planning band.

Formula and methodology

Heart-rate reserve: maximum HR - resting HR. A boundary is resting HR + percentage x reserve.

Percent maximum: percentage x maximum HR.

Age estimate: 208 - 0.7 x age, from Tanaka and colleagues. Age-predicted values have individual error, so the source remains visible in the result.

Worked examples

Measured HRR example

With maximum 185 bpm and resting 55 bpm, reserve is 130 bpm. The 60% boundary is 55 + 0.60 x 130 = 133 bpm; the 70% boundary is 146 bpm.

Age 40 estimate

208 - 0.7 x 40 = 180 bpm. This is a population regression estimate, not a measured maximum.

Interpretation and limitations

Age equations predict a population average and can miss an individual maximum.
Five-zone labels are not universal and do not equal measured lactate or ventilatory thresholds.
Medication, illness, temperature, dehydration, altitude, fatigue, and sensor error can alter heart rate.
The tool does not diagnose a condition or establish exercise safety.
Use clinician guidance when symptoms, cardiovascular risk, or medication effects are relevant.

Frequently asked questions

What is heart-rate reserve?

Maximum heart rate minus resting heart rate. The HRR method applies intensity to that reserve, then adds resting heart rate.

Is Zone 2 always 60-70%?

No. This calculator labels 60-70% as Zone 2 in a transparent five-band convention; other systems use different boundaries.

Should I use measured or age-estimated maximum?

A relevant, safely obtained measured value is generally more individual than a population age equation.

Why does my watch show different zones?

The device may use a different maximum, resting value, threshold test, or percentage scheme.

Are these zones medical advice?

No. They are planning arithmetic and do not determine exercise safety or replace qualified clinical guidance.

Sources and transparency

CalculatorGeek independently recomputed the public fixtures on 2026-09-27. Sources establish the method or its safe interpretation; they do not make a field estimate equivalent to laboratory measurement or individualized professional advice.