DocomintHeart Rate Zone Calculator
Calculate target heart rate training zones from age — fat burn, cardio, and peak.
Training zones are defined as percentage bands of estimated maximum heart rate (220 minus age, a population-level formula) — from a light warm-up pace up to a maximum-effort zone — used by runners and cyclists to target a specific training effect (fat-burning endurance vs. cardiovascular peak effort) rather than just running at whatever pace feels arbitrary.
Example: At age 35, estimated max heart rate is 185 bpm — the "fat burn" zone (60–70%) falls between 111–130 bpm, while the "cardio" zone (70–80%) runs 130–148 bpm, a noticeably different effort level for the same workout duration.
How it works
- Enter your age
- Press Calculate Zones
- Five heart rate training zones, in beats per minute, appear instantly, computed on your device
Frequently asked questions
Is "220 minus age" an accurate max heart rate formula?
It's a widely used population-average estimate, but individual max heart rate can vary by ±10-20 beats from what the formula predicts — a lab-based fitness test gives a more personalized number if precision matters for your training.
Which heart rate zone should I train in?
It depends on your goal — lower zones (fat burn, light cardio) suit longer, lower-intensity endurance sessions, while higher zones (hard, maximum) suit shorter, high-intensity interval training. Most training plans mix multiple zones across a week rather than staying in just one.
Is my numbers uploaded anywhere?
No — Heart Rate Zone Calculator runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.