Target Heart Rate Calculator (Karvonen)

Inputs and what they mean

Maximum heart rate

— Use a measured value if possible; age-based formulas are only estimates..

Resting heart rate

— number value.

Lower intensity

— number value.

Upper intensity

— number value.

How to use it

1. Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
2. Check the breakdown to see every intermediate step.
3. Read the limitations before relying on the result.

Formula

Worked example

Max 190, rest 60, 50–70%

1. Reserve = 190 − 60 = 130 bpm.
2. 50%: 130 × 0.5 + 60 = 125 bpm.
3. 70%: 130 × 0.7 + 60 = 151 bpm.

Reading the result

The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.

Limitations and assumptions

• Not medical advice or an exercise prescription.
• Accuracy depends on the maximum heart rate entered.
• For general fitness education only — not medical advice, diagnosis or a training prescription. Prediction equations are population estimates; speak with a qualified professional before changing exercise or diet, especially with a health condition.
• The result depends on the values you enter for this target heart rate calculator (karvonen); it does not supply missing rates, rules, prices, dates, or assumptions for you.