The Fitness Heart Rate Estimator calculates an age-based maximum heart-rate estimate and uses heart-rate reserve to create a customizable training zone. Heart-rate reserve is the difference between estimated maximum heart rate and resting heart rate. This tool can help organize cardio sessions or compare zone settings. Age-based maximum heart-rate equations are estimates, and medication, fitness, temperature, stress, illness, and measurement accuracy can affect actual heart rate. Stop exercise and seek appropriate care for concerning symptoms.
Use your age in completed years.
Use a calm resting measurement, preferably collected consistently.
Enter lower and upper percentages of heart-rate reserve.
Use the bpm interval as an estimate and compare it with how you feel and any professional guidance.
Estimated maximum HR = 208 − (0.7 × Age)
Heart-rate reserve = Maximum HR − Resting HR
Target HR = Resting HR + (Reserve × Zone percentage)
The lower and upper percentages are converted from percent to decimal before multiplication.
The main result is the estimated bpm interval corresponding to the selected percentages of heart-rate reserve.
Maximum heart rate can differ substantially from an age-based estimate. Medical conditions and medications may require individualized limits.
Given: Age 35, resting heart rate 60 bpm, and a 60%–75% zone.
Calculation: Maximum = 208 − 0.7 × 35 = 183.5 bpm. Reserve = 183.5 − 60 = 123.5. Lower = 60 + 123.5 × 0.60 = 134.1. Upper = 60 + 123.5 × 0.75 = 152.6.
Result: Estimated zone is 134–153 bpm.
Heart-rate reserve incorporates resting heart rate, which can make zones more individualized than a simple percentage of maximum.
Measure under similar calm conditions and use a representative value rather than a single unusual reading.
Yes. Some medications and medical conditions alter heart-rate response, so general formulas may be unsuitable.
The calculator will show an error. Enter an upper value equal to or greater than the lower value.
No. It is an estimate from an equation and cannot replace supervised testing or clinical advice.