Heart rate zone calculator

Your five training zones, from three published formulas rather than one — because they disagree, and the disagreement matters.

1 · About you

Age in years

Resting heart rate (optional)

Measure it on waking, before getting up. Supplying it switches to the Karvonen method, which uses heart rate reserve and gives noticeably different zones.

2 · Maximum heart rate, three ways

Maximum heart rate by formula
Formula	Estimate	About it

3 · Your zones

Training zones in beats per minute
Zone	Beats per minute	What it feels like

These are population estimates, not measurements. The only way to know your own maximum is a supervised test. Beta blockers and several other medicines lower heart rate directly, which makes every formula here meaningless. If you have a heart condition, take such medication, or are returning to exercise after illness, ask a doctor rather than a calculator. This is not medical advice.

Three formulas, not one

Everybody knows 220 minus age. It is worth knowing where it came from: a 1971 review by Fox, whose authors did not present it as predictive. Its variation between individuals is roughly 10 to 12 beats per minute, so for about one person in three it is out by more than ten beats, and it under-predicts systematically in older adults.

This shows three published estimates side by side and the spread between them:

Fox — 220 minus age. The familiar one.
Tanaka — 208 minus 0.7 times age, from a 2001 meta-analysis. Generally the better fit, particularly over 40, and the default here.
Gellish — 207 minus 0.7 times age, from a 2007 longitudinal study.

Showing the disagreement is the point. A single number implies a precision that does not exist.

Karvonen, if you know your resting rate

Enter a resting heart rate and the zones are calculated from heart rate reserve — maximum minus resting — rather than as flat percentages of maximum. For a fitter person with a low resting rate this gives noticeably different numbers, and it is the method most coaches use. Measure your resting rate on waking, before getting up.

The five zones

Zone 1 is recovery, zone 2 the endurance base where you can still hold a conversation, zone 3 aerobic, zone 4 threshold, zone 5 maximum. The boundaries are a convention for talking about effort, not thresholds that exist in the body.

Example

At 40, Fox gives 180, Tanaka 180 and Gellish 179. At 70 they give 150, 159 and 158 — a nine-beat spread, which is exactly why one number is not enough.

This is not medical advice

These are population estimates. The only way to know your own maximum is a supervised test. If you have a heart condition, take medication that affects heart rate — beta blockers in particular make every formula here meaningless — or are returning to exercise after illness, ask a doctor rather than a calculator.