How it's calculated
The calculator first estimates your maximum heart rate from your age, then works out target heart-rate ranges as percentages of it.
- 220 − age is the long-standing rule of thumb. The American Heart Association uses it in its target heart rate worksheet.AHA
- 208 − 0.7 × age comes from Tanaka, Monahan and Seals (2001), who pooled 351 studies with 18,712 people and then tested the equation in 514 healthy adults in the laboratory. They found 220 − age underestimates maximum heart rate in older adults, and that the relationship didn't differ between men and women or with activity level.J Am Coll Cardiol
Target ranges use the American College of Sports Medicine percentages of maximum heart rate: 65–75% for moderate-intensity exercise and 76–96% for vigorous; below 65% is light. CDC's guidance on measuring intensity links to these figures. The American Heart Association uses slightly broader bands, so expect small differences between charts.American College of Sports Medicine
If you add your resting heart rate, the calculator also uses the heart rate reserve (Karvonen) method, which sets targets between your resting and maximum rates.
This is an estimate for general information, not medical advice.
The formula
- Max heart rate = 220 − age, or 208 − 0.7 × age.
- Moderate range = 0.65 × max to 0.75 × max. Vigorous range = 0.76 × max to 0.96 × max.
- Heart rate reserve = max − resting heart rate.
- Reserve target = resting + reserve × intensity (for example 50%).
Worked example
At 35, the 220 − age rule gives a maximum of 185 beats per minute, so moderate exercise is 120–139 bpm and vigorous exercise is 141–178 bpm.
The AHA worksheet's reserve example uses a 50-year-old with a resting rate of 72: maximum 220 − 50 = 170, reserve 170 − 72 = 98, and half the reserve added to the resting rate gives 121 bpm at 50% of reserve.
At 65, the two formulas differ more: 220 − age gives 155, while Tanaka gives 163.
Estimated max heart rate: 177 BPM · 208 − 0.7 × AGE (TANAKA)
Assumptions and limitations
- Averages, not your personal maximum. Both formulas predict the average for people your age. Your real maximum can be higher or lower; studies like Tanaka's measure it with maximal exercise tests in a laboratory.
- Resting heart rate. The AHA describes a normal resting rate as 60 to 100 beats per minute, and notes an athlete's can be as low as 40. Take it sitting calmly: count your pulse for 10 seconds and multiply by 6.
- Percent of max vs percent of reserve. The ACSM ranges are percentages of maximum heart rate, not of reserve, so a reserve target and a max-based range at the same percentage are different numbers.
- Talk test. Heart rate is one way to gauge effort. CDC's simpler guide is that during moderate activity you can talk but not sing.CDC
- Health conditions. If you have a heart condition or take medicine that affects your heart rate, ask your doctor what range is right for you.
To plan run times at a target effort, use the pace calculator.