Target Heart Rate Calculator

Karvonen Method Training Zones

Enter your age and resting heart rate to calculate your personalized training heart rate zones.

Parameters

Age

Resting HR (bpm)

Moderate Zone (50-70%)

Enter your details to see your target zones.

Validation Error

Please provide a valid age and resting heart rate to proceed.

Understanding Target Heart Rate Zones

The Karvonen method accounts for your resting heart rate — a proxy for cardiovascular fitness — giving a more personalized target zone than simply using a percentage of max heart rate alone.

Moderate Intensity (50-70%)

Suitable for building an aerobic base, active recovery, and longer-duration cardio sessions.

Vigorous Intensity (70-85%)

Associated with greater cardiovascular fitness improvements, used in interval training and higher-intensity cardio.

Why Resting Heart Rate Matters

A lower resting heart rate generally reflects better cardiovascular conditioning — the Karvonen method uses this to individualize your zones.

Medications Can Shift This

Beta-blockers and other heart medications can lower your actual max heart rate below the formula estimate.

The Karvonen Formula

\[ THR = ((HR_{max} - HR_{rest}) \times \%\text{Intensity}) + HR_{rest} \]

Where HRmax is estimated as 220 minus your age, and HRrest is your measured resting heart rate. This is also called the Heart Rate Reserve (HRR) method.

Important Limitations

220-age is a rough estimate: Individual max heart rate can vary by ±10-15 bpm from this formula.
Resting HR should be measured properly: Take it first thing in the morning, before getting out of bed, for the most accurate reading.
Medications and conditions affect heart rate: Beta-blockers, thyroid conditions, and other factors can shift your actual max and resting heart rate.

Key Takeaways

The Karvonen method personalizes your zones. It factors in your resting heart rate, not just age.
Moderate and vigorous zones serve different goals. Choose based on whether you're building an aerobic base or pushing for fitness gains.
Measure resting HR consistently. The same time of day and conditions give the most reliable input.
Consult a professional. If you take heart medication (e.g., beta-blockers) or have a cardiac condition, ask your doctor for a personalized target zone instead of relying on the Karvonen estimate.

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