Heart Rate Zone Calculator
Training in the right zone is the difference between building endurance and just getting tired. Enter your age and get all five heart-rate zones — from easy recovery to all-out — using the research-backed Tanaka formula for max heart rate.
Optional resting HR unlocks Karvonen zones, which personalize better for fit individuals. A lab or field test beats any formula.
The Tanaka formula
More accurate than the old “220 minus age,” especially past 40. Enter a resting heart rate to switch to Karvonen zones, which account for your fitness level via heart-rate reserve.
How to use the zones
- 80% of cardio in Zone 2: the polarized-training approach behind most endurance progress.
- Zone 4–5 in small doses: 1–2 interval sessions weekly is plenty.
- Zone 1: active recovery — you should be able to hold a full conversation.
Frequently asked questions
What is max heart rate?
The highest rate your heart can sustain in all-out effort. It declines with age and varies individually — formulas estimate it within ~10 bpm.
Is 220 minus age accurate?
Roughly, but it overestimates for younger people and underestimates past 40. The Tanaka formula (208 − 0.7 × age) fits research data better.
What is Zone 2 training?
Easy aerobic work at 60–70% of max HR — you can talk in full sentences. It builds mitochondrial efficiency and is the foundation of endurance.
Do I need a heart-rate monitor?
For zone discipline, yes — perceived effort drifts. A basic chest strap or watch works fine.
What’s the Karvonen method?
It sets zones from heart-rate reserve (max minus resting) instead of max alone, personalizing zones for fitter people with low resting rates.