Max Heart Rate (MHR): The estimated upper limit of beats per minute your heart can sustain during all-out effort. Individual MHR can vary by 10–20 bpm from the 220-minus-age estimate.
Warm-up zone (50–60%): Very light effort — walking, gentle cycling. Good for recovery days and pre-workout warm-ups.
Fat Burn zone (60–70%): Moderate effort where a higher percentage of calories come from fat, though total calorie burn is lower than harder zones.
Cardio zone (70–80%): Steady-state endurance work — this is where most aerobic fitness gains happen.
Peak zone (80–90%): Hard interval territory that builds speed and anaerobic capacity. Sustainable for only a few minutes at a time.
How This Calculator Works
You enter your age and the tool applies the classic 220-minus-age formula to estimate your maximum heart rate. It then multiplies that max by standard percentage ranges to define five training zones: warm-up, fat burn, cardio, peak, and max. The formula assumes average physiology — actual max HR varies with genetics, fitness, and testing conditions.
Quick Questions
How accurate is the 220-minus-age formula?
It gives a reasonable population average but can be off by 10–20 bpm for any individual. If you need precise zones, a graded exercise test with a cardiologist or sports physiologist is the gold standard.
What is the resting heart rate field for?
It is included for a future Karvonen-method update that uses resting HR to personalize zones. Currently the calculator uses the simpler percentage-of-max approach, which does not require resting HR.
Which zone should I train in most?
For general cardiovascular fitness, most training time should fall in the cardio zone (70–80%). Mix in warm-up zone work for recovery and peak zone intervals once or twice a week for speed and VO2 max improvements.
Should I consult a doctor before using heart rate zones?
Yes, especially if you have a heart condition, high blood pressure, or are new to vigorous exercise. A physician can help determine safe intensity levels for your situation.
Estimate only. Results reflect your inputs and standard formulas — they are not financial, tax, legal, health, or investment advice. Verify important decisions with a qualified professional.