Rex says
Same equations the textbooks use — just way less awkward. Pop in your stats and I'll tell you what the number actually means for you.
Try a scenario
Click to load — tweak from there.Inputs
Result
Estimated max HR
190
Zone 1 (recovery)
125–138 bpm
Zone 2 (endurance)
138–151 bpm
Zone 3 (tempo)
151–164 bpm
Zone 4 (threshold)
164–177 bpm
Zone 5 (VO2 max)
177–190 bpm
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter age.
- 2Enter resting hr (optional, for karvonen).
- 3Read your estimated max hr on the right — it updates as you type.
- 4Hit Share to keep the scenario or send it to someone.
About this calculator
Estimates max heart rate (220 − age) and the standard training zones.
Worked example
Using the values the calculator loads with:
Inputs
- Age: 30
- Resting HR (optional, for Karvonen): 60
Results
- Estimated max HR: 190
- Zone 1 (recovery): 125–138 bpm
- Zone 2 (endurance): 138–151 bpm
- Zone 3 (tempo): 151–164 bpm
- Zone 4 (threshold): 164–177 bpm
- Zone 5 (VO2 max): 177–190 bpm
What each field means
Inputs
- Age
- The age used in the calculation. Starts at 30 so you have a working example on load. Accepted range: 1–120.
- Resting HR (optional, for Karvonen)
- The resting hr (optional, for karvonen) used in the calculation. Starts at 60 so you have a working example on load. Accepted range: 30–120.
Results
- Estimated max HR
- Returned as a whole number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Zone 1 (recovery)
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Zone 2 (endurance)
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Zone 3 (tempo)
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Zone 4 (threshold)
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Zone 5 (VO2 max)
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the target heart rate calculator work?
Estimates max heart rate (220 − age) and the standard training zones.
What do I need to enter?
2 values: age, and resting hr (optional, for karvonen). Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the estimated max hr result mean?
It is returned as a whole number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
Who is this tool for?
It's built for anyone tracking a health or training target and wanting the standard formula applied correctly, without a signup or an app.
Accuracy and limitations
- Population formulas describe averages; individual bodies vary, especially at the extremes of height, age, or muscle mass.
- Results do not account for medical conditions, medication, or pregnancy.
- Use this as a directional reference, not a diagnosis — talk to a clinician before acting on it.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Heart Rate Zones Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/heart-rate
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/heart-rate" target="_blank" rel="noopener">Heart Rate Zones Calculator — RevenueLab</a> (2026).</p>
Source: [Heart Rate Zones Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/heart-rate) (2026).