Toolrack

Heart Rate Zone Calculator

Works offlineNothing is uploadedFree, no sign-up
measure lying down, before getting up
From a test or a race — overrides the age formula.
MAX HEART RATE—
Z1 · RECOVERY—
Z2 · ENDURANCE—
Z3 · TEMPO—
Z4 · THRESHOLD—
Z5 · MAXIMUM—

Computed in this tab — nothing you enter leaves it.

Five training zones from your age — maximum heart rate by Tanaka's 208 − 0.7 × age, the formula that replaced the fossil 220 rule in the literature — and, when you know your resting pulse, the Karvonen reserve method that anchors every zone to your actual fitness.

Zones are percentages of the right ceiling

All five zones are fractions — 50 to 100 percent — of a ceiling. The whole question is which ceiling: a formula's maximum, or your reserve between resting and maximum. The second needs one more number and is worth it: resting heart rate is the cheapest fitness measurement there is, and it converts generic bands into yours.

The bands themselves — 50/60/70/80/90 — are the convention the endurance world settled on. The craft is not in the boundaries; it is in spending most of your time under the third one.

Frequently asked questions

What is each zone actually for?

Z1 is active recovery — conversation is easy. Z2 builds the aerobic base and burns predominantly fat; most training time belongs here. Z3 is sustained tempo. Z4 sits at the lactate threshold, the pace you can hold for about an hour. Z5 is intervals measured in minutes — sharpening, not building.

Why Tanaka instead of 220 minus age?

The 220 rule was never derived — it was a 1970 back-of-envelope reading of other people's charts. Tanaka's 208 − 0.7 × age comes from a meta-analysis of 351 studies and stops under-predicting older athletes: at fifty the two formulas already disagree by three beats, and the gap grows.

What does the resting rate change?

It personalises the zones. Percent-of-max treats a sedentary and a trained heart with the same maximum identically; Karvonen works on the reserve — max minus resting — so a lower resting pulse shifts every zone upward. Two people of one age can train forty beats apart, correctly.

Should I trust these zones or a lab test?

Formulas estimate; a lactate or ramp test measures. Maxima vary by roughly ±10 beats around any age formula. Use these zones to structure training sensibly, and treat persistent mismatch — Z2 feeling like a sprint — as a reason to test, not to push.

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