Heart Rate Zone Calculator
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Calculate Zones
Heart Rate Zone Calculator Guide
Heart rate training zones divide your exercise intensity into 5 bands based on a percentage of your maximum heart rate (MHR). Each zone triggers different physiological adaptations — from fat burning in Zone 1 to explosive peak performance in Zone 5.
Using the Karvonen method, MHR = 190, Heart Rate Reserve (HRR) = 125 bpm:
Karvonen Method (HRR)
Most accurate method. Accounts for your resting heart rate, giving personalised zones rather than generic percentages.
% of Max HR Method
Simple and widely used. Good for beginners. Multiply your max heart rate by zone percentages — no resting HR needed.
Fox Formula (Beginner)
Classic formula. Simple, widely used, ±10–12 bpm accuracy.
Tanaka Formula (Intermediate)
More accurate for active adults. Validated by a 2001 meta-analysis of 18,712 subjects.
Gelish Formula (Athletic)
Recommended for trained athletes. Adjusted for higher cardiovascular efficiency.
Zone 1 — Warm Up
50–60% MHR · Very light effort
Recovery, warm-up, cool-down. Burns fat as primary fuel. Sustainable for hours.
Zone 2 — Fat Burn
60–70% MHR · Light effort
Optimal fat oxidation zone. Builds aerobic base. Can hold a conversation.
Zone 3 — Cardio
70–80% MHR · Moderate effort
Improves cardiovascular efficiency. Burns more calories. Harder to talk.
Zone 4 — Anaerobic
80–90% MHR · Hard effort
Increases lactate threshold. Boosts speed and power. Only short sentences possible.
Zone 5 — Peak / VO₂ Max
90–100% MHR · Maximum effort
Short sprints and HIIT. Maximises VO₂ max. Cannot be sustained for more than a few minutes.
Q1: Which zone burns the most fat?
Zone 2 (60–70% MHR) burns the highest percentage of calories from fat. For total calorie burn, Zone 4–5 burns more overall, but Zone 2 is optimal for fat oxidation and weight loss.
Q2: How do I find my resting heart rate?
Measure it first thing in the morning before getting out of bed. Count your pulse for 60 seconds. The average adult RHR is 60–80 bpm; fit athletes can be as low as 40 bpm.
Q3: How long should I train in each zone?
A popular split is the 80/20 rule: 80% of training in Zone 1–2 (aerobic base) and 20% in Zone 4–5 (high intensity). This prevents overtraining while maximising performance gains.
Q4: Karvonen vs % of Max HR — which is better?
Karvonen is more accurate as it accounts for your resting heart rate. Use Karvonen if you know your RHR. Use % of Max HR for a quick, simple estimate.