Target Heart Rate Calculator
Find the heart rate for a chosen training intensity with the Karvonen method, which uses your resting heart rate as well as your age, plus all five zones.
The heart rate to train at for the effort you want, using your resting pulse.
How the target heart rate calculator works
The Karvonen method works with heart-rate reserve — the gap between your resting and maximum heart rate — so two people of the same age with different fitness get different targets. Target = resting + intensity × (maximum − resting). Maximum is estimated with the Tanaka formula (208 − 0.7 × age); enter a measured maximum in Detailed mode if you know it.
The zones below the result use the common 50–60% (very light), 60–70% (light, fat-burning), 70–80% (aerobic), 80–90% (threshold) and 90–100% (maximal) bands of heart-rate reserve.
Formula: THR = RHR + intensity × (HRmax − RHR)
Worked examples
| Inputs | Target heart rate | Note |
|---|---|---|
| Age 30, resting 65, 70% | 150 bpm | reserve 122, target 150 |
| Age 30, resting 50, 70% | 146 bpm | a fitter heart, lower target |
| Age 55, resting 70, 60% | 130 bpm | a light session |
FAQFrequently asked questions
Why include resting heart rate?
Because fitness lowers it. Two 30-year-olds with resting rates of 50 and 75 have different reserves, so a fixed percentage of maximum would set the fitter one too easy a target. Karvonen scales the intensity to the reserve.
Which zone should I train in?
Most endurance training sits in zones 2–3, with shorter efforts in zones 4–5. A typical week puts most time in the easier zones and a small share in the hard ones.
How do I measure resting heart rate?
Count your pulse for a full minute before getting out of bed on a few mornings and take the average, or read it from a watch that records it overnight.
My maximum from a test is different — can I use it?
Yes. Open Detailed mode and enter it; the calculator then ignores the age formula.
Where these figures come from
- Mifflin MD et al., "A new predictive equation for resting energy expenditure in healthy individuals", Am J Clin Nutr 1990 — the BMR equation used here
- World Health Organization — Waist circumference and waist–hip ratio (2008 expert consultation) — waist-to-hip cut-offs
- Tanaka H, Monahan KD, Seals DR, "Age-predicted maximal heart rate revisited", J Am Coll Cardiol 2001 — 208 − 0.7 × age
- Nathan DM et al., "Translating the A1C assay into estimated average glucose values" (ADAG), Diabetes Care 2008 — eAG = 28.7 × A1c − 46.7
- Mosteller RD, "Simplified calculation of body-surface area", N Engl J Med 1987 — BSA = √(height × weight / 3600)
- Australian Department of Health and Aged Care — national health guidance
Last checked: September 2026. The equations are fixed by their published papers and do not change with tax years or regulations; the thresholds quoted in verdicts name the body that set them.