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Target Heart Rate (Karvonen)

Calculate target training heart rate using the Karvonen Heart Rate Reserve method (Ann Med Exp Biol Fenn, 1957), the gold standard for exercise prescription.

Measure first thing in the morning
70
Typical fat burn: 60-70%, aerobic: 70-80%

Results

Estimated HRmax208 bpm
Heart Rate Reserve208 bpm
Target Heart Rate146 bpm

📖What is it?

Calculates your target training heart rate using the Karvonen Heart Rate Reserve (HRR) method, the gold standard for exercise prescription. Unlike simple percentage-of-HRmax methods, Karvonen accounts for your resting heart rate, giving a more individualized and accurate training intensity.

🎯How to use

Enter your age, resting heart rate (measured first thing in the morning), and desired training intensity percentage. The calculator derives HRmax (Tanaka formula), subtracts resting HR to get HRR, then applies your intensity percentage.

💡Example scenario

A 30-year-old with a resting HR of 60 bpm at 70% intensity: HRmax = 208 − 0.7 × 30 = 187 bpm, HRR = 187 − 60 = 127 bpm, THR = 127 × 0.70 + 60 = 149 bpm. This accounts for their fitness level — a fitter person with lower resting HR gets a higher target.

🏆Pro tip

Measure resting HR over 3–5 mornings and average the values for accuracy. As your cardiovascular fitness improves, your resting HR drops, automatically shifting your Karvonen training zones upward — recalculate every 4–6 weeks.