Target Heart Rate Calculator

Training by heart rate keeps your effort honest — it tells you whether you’re working easy, moderate, or hard regardless of how you feel. This calculator estimates your maximum heart rate and maps out five training zones in beats per minute, personalised with your resting heart rate.

How your zones are calculated

The calculator works in two steps:

1. Maximum heart rate. The common estimate is 220 − age. We also offer the Tanaka (208 − 0.7 × age) and Nes (211 − 0.64 × age) formulas, which research suggests are more accurate, especially for older adults. If you’ve done a maximal test and know your real max HR, enter it in the optional field and the zones use that instead.

2. The zones. Each zone is a share of your heart-rate reserve (max minus resting) using the Karvonen formula:

   target BPM = ((max HR − resting HR) × intensity) + resting HR

Because it includes your resting rate, Karvonen gives ranges tailored to your fitness rather than a generic percentage of maximum.

A worked example

Take a 30-year-old with a resting heart rate of 60 bpm. Their estimated max is 220 − 30 = 190 bpm, and their heart-rate reserve is 190 − 60 = 130 bpm. To find the aerobic Zone 3 (70–80%): the low end is (130 × 0.70) + 60 = 151 bpm and the high end is (130 × 0.80) + 60 = 164 bpm. That is how to calculate target heart rate zones by hand — the calculator just does it for all five zones at once.

The five zones

Zone	% of reserve	Purpose
1 — Warm-up	50–60%	Recovery, easy warm-up
2 — Fat burn	60–70%	Building aerobic base
3 — Aerobic	70–80%	Improving endurance
4 — Anaerobic	80–90%	Speed and performance
5 — Maximum	90–100%	Short, hard intervals

Using heart-rate training

Most of your training should sit in Zones 1–3, with shorter, harder efforts in Zones 4–5. These figures are estimates — the max-HR formulas carry a spread of about ±10 bpm from person to person — so treat them as a guide and adjust to how you feel. If you have a heart condition or are new to exercise, check with a doctor before training at the higher intensities. To translate that effort into running pace, see the pace calculator; for a fitness score built on the same aerobic system, the VO₂ max calculator estimates it.