What this calculator does
Karvonen target heart rate works out target heart rate training zone from heart rate reserve, using the Karvonen formula. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
FormulaTarget HR = ((220 − age − resting HR) × %intensity) + resting HR (Karvonen, 1957)
The inputs explained
| Field | What to enter |
|---|---|
| Age (years) | A number, measured in years. Starts at 35. |
| Resting heart rate (bpm) | A number, measured in bpm. Starts at 65. |
| Lower intensity (%) | A number, measured in %. Starts at 50. |
| Upper intensity (%) | A number, measured in %. Starts at 75. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with age
Every other input is held at the calculator’s starting values while age varies. Select any row to load that scenario into the calculator.