Heart Rate Calculator
Calculate your maximum heart rate and target heart rate zones for fat burning, cardio, and peak performance.
About this calculator
Your heart rate tells you how hard you are working. This calculator estimates your maximum heart rate from your age, and then uses your resting heart rate to build five training zones with the Karvonen method, which is more personal than a plain percentage of maximum.
Zone 1 is a warm-up or recovery effort, zone 2 builds endurance and burns a high share of fat, zone 3 is steady cardio, zone 4 is hard threshold work and zone 5 is a short maximum effort. Most of your training time should be in zones 2 and 3.
How to use it
- Enter your Age.
- Enter your Resting Heart Rate, measured in the morning before getting up.
- Press Calculate.
- Read your maximum heart rate, heart rate reserve and the five zones.
Karvonen method
Max HR = 220 − age. Heart rate reserve = Max HR − Resting HR. Zone limit = Resting HR + Reserve × intensity %. The zones use 50 to 60%, 60 to 70%, 70 to 80%, 80 to 90% and 90 to 100% of the reserve. The 220 minus age rule is an average and can be off by 10 beats or more for an individual.
Worked example
Age 30, resting heart rate 65
| Max heart rate | 190 bpm |
| Reserve | 125 bpm |
| Zone 1 (50 to 60%) | 128 to 140 |
| Zone 2 (60 to 70%) | 140 to 153 |
| Zone 3 (70 to 80%) | 153 to 165 |
| Zone 4 (80 to 90%) | 165 to 178 |
| Zone 5 (90 to 100%) | 178 to 190 |
This tool gives general information, not medical advice. Talk to a doctor or dietitian before making changes to your diet, exercise or medication.
Tips and common mistakes
- Measure your resting heart rate for three mornings and average it.
- Most training should be in zones 2 and 3. Keep zones 4 and 5 for one or two sessions a week.
- Medications such as beta blockers lower heart rate. Ask your doctor about targets.
- If you feel dizzy, short of breath or have chest pain, stop and seek advice.
- A fitness test gives a truer maximum than any formula.
Frequently asked questions
How do I calculate my maximum heart rate?
The common estimate is 220 minus your age.
What is the Karvonen formula?
It sets zones as a share of heart rate reserve added to your resting rate.
What heart rate burns the most fat?
Zone 2, around 60 to 70% of reserve, uses the highest proportion of fat, though total calories matter more.
What is a normal resting heart rate?
60 to 100 beats a minute for adults; fit people are often lower.
Is 220 minus age accurate?
It is an average. Individuals vary by 10 to 20 beats.
Should I train in zone 5 often?
No. It is hard and best used sparingly.