Tools

HEART RATE ZONE CALCULATOR

Dial in your cardio zones with three methods — %MaxHR, Karvonen heart-rate reserve, or Friel’s LTHR zones.

Method
Formula
About this method

%MaxHR estimates your max heart rate from age (and sex for Tanaka/Gulati) and distributes zones as percentages. Tanaka (men) and Gulati (women) are the research-backed defaults — they account for sex-based differences and are more accurate than the classic 220-age rule. 220-age is offered as a familiar, quick option if that's what you know; expect ±10–15 bpm error versus ±7 bpm for Tanaka/Gulati.

Sex

Max HR

184 bpm

Tanaka: 208 − 0.7 × 35

Training zones

ZoneBPM%Purpose

Z1

Recovery

92–11050–60%Warm-up, cool-down, easy recovery efforts.

Z2

Endurance

110–12960–70%Aerobic base — long, conversational efforts.

Z3

Tempo

129–14770–80%Steady, moderately hard aerobic work.

Z4

Threshold

147–16680–90%Lactate-threshold intervals.

Z5

VO2 Max

166–18490–100%Short, maximal intervals — top-end fitness.

Training-zone guide

What each zone feels like and what it develops.

  • Z1 — Recovery

    Easy, conversational. Active recovery, warm-ups, and cool-downs.

  • Z2 — Endurance

    Aerobic base. Long, steady efforts you could hold for hours.

  • Z3 — Tempo

    Moderately hard. Breathing deeper; talking is possible but choppy.

  • Z4 — Threshold

    Comfortably hard. Sustainable for 20–60 minutes; short phrases only.

  • Z5 — VO2 / Anaerobic

    Very hard to maximal. Short intervals that build top-end fitness.

Sources & further reading

This calculator is an educational estimator. Talk to your physician before starting a new training program, especially if you have a cardiac condition or take medications that affect heart rate.