By Zencalcy Editorial TeamLast reviewed About us
Find the heart rate range that sits in the fat burning zone, along with the wider set of training zones around it. The calculator estimates your maximum heart rate from your age and turns it into beats per minute targets.
Find your fat burning heart rate zone and other ranges.
max HR = 220 − age fat burning (Zone 2) = 60–70% of max HR other zones: 50–60%, 70–80%, 80–90% Karvonen target = resting HR + (max HR − resting HR) × zone %
The simple 220 minus age estimate is a rough average. Your true maximum can differ by ten beats or more, so treat the ranges as guideposts and adjust to how you feel.
| Symbol | Meaning |
|---|---|
| age | Your age in years, used to estimate maximum heart rate. |
| resting HR | Optional resting heart rate for the Karvonen method. |
| zones | Percentage bands applied to your maximum heart rate. |
At age 35 the estimated maximum is 185 bpm, so the fat burning zone runs from about 111 to 130 bpm. The aerobic zone sits higher, roughly 130 to 148 bpm.
Heart rate training zones are built from an estimate of maximum heart rate, most simply 220 minus your age, a formula known to be rough with meaningful individual error. The commonly cited fat burning zone spans roughly 60 to 70 percent of that maximum, which is a comfortable, conversational pace for most people.
The calculator finds those boundaries by multiplying your estimated maximum by the zone percentages, giving the beats per minute you would aim to hold during steady cardio work.
At lower intensity the body draws a larger share of its energy from fat, but the total calories burned per minute are lower. At higher intensity the fat share falls yet total energy use rises, so the absolute amount of fat burned can be similar or greater. The zone is about the mix of fuels, not a magic switch.
The often repeated claim that low intensity burns more fat in total oversimplifies this trade off. For most people, total energy expenditure and consistency matter more than staying in a narrow band, and any activity you will actually repeat beats a precise zone you avoid.
Continue with the Hiking Calorie Calculator, Jump Rope Calorie Calculator, or the Running Calorie Calculator — or browse more calories burned tools and all sports calculators.
It burns a higher share of calories from fat, but total calories and consistency matter more for fat loss. Higher intensity burns more total energy in the same time.
Every result is computed locally in your browser from the formulas shown above. Nothing you type is uploaded, logged, or stored, and no account is required.
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Last reviewed: September 2026. See how we build and check every tool on the about page.
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Content updated: September 2026