Heart Rate Zone Calculator

Calculate target BPM for exercise with age-predicted or measured maximum heart rate. Compare five common training bands using percentage of maximum heart rate or heart-rate reserve.

Target BPMSet any intensity range from 30% to 100% and see its heart-rate target.

Two zone methodsCompare percentage of maximum with the resting-rate-aware heart-rate-reserve method.

Private by designNothing you enter is uploaded, stored, or used to track you.

Calculate exercise heart-rate zones

For adults. This is an educational estimate—not an exercise prescription, fitness clearance, diagnosis, or safety limit.

Prepared by: Starlight Tools editorial team. Last reviewed: July 30, 2026.

Method basis: AHA general target ranges, the common 220 − age estimate, the Tanaka age equation, and the heart-rate-reserve calculation. Sources are linked below.

Privacy: Inputs and results remain in this browser tab. This tool does not send or save them.

1. Choose maximum heart rate

Maximum heart-rate source

Age (years) This calculator limits age-based estimates to adults aged 18–100.

2. Choose zone method

Calculation basis Percentage of maximum is simpler. Heart-rate reserve also uses resting heart rate.

3. Set your target intensity

Lower intensity (%)

Upper intensity (%)

The default 50–85% span matches the AHA's broad general target range when percentage of maximum is selected. Five-zone labels vary between training systems.

Your target heart-rate results

Enter your values and select Calculate zones.

—

Custom target range in beats per minute

Maximum heart rate used—

Zone calculation basis—

Heart-rate reserveNot used

The separate AHA general guide based on percentage of maximum will appear here.

Five common heart-rate training zones
Zone	Intensity	Target BPM
Zone 1	50–60%	—
Zone 2	60–70%	—
Zone 3	70–80%	—
Zone 4	80–90%	—
Zone 5	90–100%	—

How to use target heart-rate zones

Choose a maximum-heart-rate source. Age equations are convenient averages. Use measured maximum only when the value comes from an appropriate, credible test.
Choose the basis. Percentage of maximum uses only maximum heart rate. Heart-rate reserve also uses resting heart rate and therefore produces different BPM boundaries.
Calculate and compare. The large result shows your custom range. The table shows five common 10-percentage-point bands.
Use more than one signal. Perceived effort, breathing, the talk test, heat, hydration, terrain, fatigue, and symptoms also matter.

Formulas and assumptions

Maximum heart-rate options

AHA simple estimate: HRmax ≈ 220 − age

Tanaka estimate: HRmax ≈ 208 − (0.7 × age)

Both predict a population average, not a personal ceiling. The Tanaka equation was derived from a meta-analysis and laboratory validation in healthy adults. Neither equation proves that maximal exertion is safe.

Zone calculation options

Percent max: Target HR = HRmax × intensity

Heart-rate reserve: Target HR = resting HR + [(HRmax − resting HR) × intensity]

For display, final zone boundaries are rounded to the nearest whole beat per minute. Calculations use the unrounded maximum-heart-rate value.

There is no universal five-zone naming system. Watches, coaches, labs, and apps may use different inputs and boundaries. This page uses 50–60%, 60–70%, 70–80%, 80–90%, and 90–100% as transparent comparison bands.

Safety and medical limits

Do not treat a calculated zone as proof that an intensity is safe. If you have known heart or lung disease, a chronic condition, are pregnant, are returning after a long period of inactivity, or take medicine that affects heart rate, ask a qualified health professional what exercise intensity and monitoring method are appropriate for you.

Warm up and cool down gradually. Stop exercise and seek appropriate medical help for chest pain or pressure, fainting, marked dizziness or confusion, unusual or extreme shortness of breath, or a fast or uneven heartbeat that feels concerning. Follow local emergency guidance when symptoms may be urgent.

Heart rate can be changed by medication, illness, dehydration, heat, altitude, caffeine, stress, poor sleep, and sensor error. Wrist optical sensors may lag or misread during movement. A normal-looking number does not override symptoms.

Worked example

For a 40-year-old using the AHA simple estimate:

Estimated HRmax = 220 − 40 = 180 bpm

Using percentage of maximum, the AHA general moderate range is approximately 90–126 bpm (50–70%), and the vigorous range is approximately 126–153 bpm (70–85%).

If the same person has a resting heart rate of 60 bpm and selects heart-rate reserve, a 60–70% range becomes:

60 + [(180 − 60) × 0.60] to 60 + [(180 − 60) × 0.70] = 132–144 bpm

This difference is expected: 60–70% of heart-rate reserve is not the same calculation as 60–70% of maximum heart rate.

Sources and methodology

American Heart Association. Target Heart Rates Chart. General maximum-heart-rate estimate and 50–70% moderate / 70–85% vigorous guidance; last reviewed August 12, 2024.
Tanaka H, Monahan KD, Seals DR. (2001). Age-predicted maximal heart rate revisited. Journal of the American College of Cardiology, 37(1), 153–156. PubMed record.
American Society for Preventive Cardiology. (2022). Clinical practice statement on physical activity, cardiorespiratory fitness, and exercise intensity. Discusses target heart rate, percentage of maximum, and heart-rate-reserve methods and their limitations.
American Heart Association. Develop a Physical Activity Plan for You. Exercise warning signs and gradual warm-up/cool-down guidance; last reviewed April 24, 2024.

Method note: the calculator retains decimal precision internally and rounds displayed BPM to the nearest whole number. It does not infer fitness, diagnose rhythm problems, evaluate wearable accuracy, or prescribe workout duration.

Heart Rate Zone Calculator FAQ

How do I calculate my target heart rate?

A simple method multiplies maximum heart rate by the desired intensity. The heart-rate-reserve method first subtracts resting heart rate from maximum heart rate, multiplies that reserve by the desired intensity, then adds resting heart rate back.

What is my maximum heart rate?

Maximum heart rate is the highest rate reached during maximal effort. Equations such as 220 − age or 208 − 0.7 × age estimate a population average. Your measured maximum may differ, and you should not attempt maximal exercise merely to obtain a number unless that testing is appropriate for you.

What is a moderate exercise heart rate?

The American Heart Association describes moderate-intensity activity as about 50–70% of maximum heart rate and vigorous activity as about 70–85%. These are broad guides, not personalized medical prescriptions.

Is the Karvonen method the same as heart-rate reserve?

The terms are commonly used together. The calculation adds resting heart rate to a selected percentage of the difference between maximum and resting heart rate.

Why do my watch and this calculator show different zones?

Devices may use different maximum-heart-rate estimates, resting-heart-rate averages, zone boundaries, rounding rules, lactate-threshold estimates, or automatic updates. Check the chosen method and inputs before comparing numbers.

Do medicines affect target heart-rate zones?

Yes. Beta blockers, some calcium channel blockers, and other medicines can change heart-rate response. Ask a qualified health professional for an appropriate exercise target if you take heart-rate-altering medicine or have a heart condition.

Does this calculator store my heart-rate data?

No. The calculation runs in your browser, and this tool does not upload, save, or track the values you enter.