How to use the Heart Rate Calculator
Enter the age and resting heart rate and the result appears straight away. Everything runs in your browser, so nothing you type is uploaded.
The formula
Max heart rate = 220 − age; Tanaka = 208 − 0.7 × age; Karvonen = (max − rest) × intensity + rest
Examples
- Age 35, resting heart rate 60
Maximum heart rate: 185 bpm (220 − age); Tanaka: 184 bpm Zone 1 recovery: 123 to 135 bpm (Karvonen) Zone 2 fat burn / easy aerobic: 135 to 148 bpm (Karvonen)
- Age 50, resting heart rate 65
Maximum heart rate: 170 bpm (220 − age); Tanaka: 173 bpm Zone 1 recovery: 118 to 128 bpm (Karvonen) Zone 2 fat burn / easy aerobic: 128 to 139 bpm (Karvonen)
- Age 25, resting heart rate 50
Maximum heart rate: 195 bpm (220 − age); Tanaka: 191 bpm Zone 1 recovery: 123 to 137 bpm (Karvonen) Zone 2 fat burn / easy aerobic: 137 to 152 bpm (Karvonen)
Limitations and assumptions
Population averages. Individual maximum heart rate can differ by 10 beats or more. General estimate for adults, not medical advice. Speak to a doctor or registered dietitian before making significant changes to diet, exercise or health routines.
Frequently asked questions
How do I estimate max heart rate?
A common rule is 220 minus age, though individual values vary by several beats a minute.
What is the Karvonen method?
It targets a percentage of heart rate reserve (max minus resting) added to resting rate, which personalises zones.
Which zone burns fat?
Moderate zones (roughly 60 to 70 percent) rely more on fat as fuel, but total energy burned matters more for weight change.
Is this medical advice?
No. Check with a doctor before starting hard training if you have a heart condition.