Heart Rate Zone Calculator

Calculate all five heart rate training zones from your age and resting heart rate.

Age

Resting Heart Rate (bpm)Measure first thing in the morning before getting up

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Enter your values and click Calculate

Training without knowing your heart rate zones is like driving without a speedometer — you might be working far too hard or barely hard enough. Heart rate zones define the intensity ranges that stress different physiological systems: fat-burning aerobic metabolism in zones 1–2, cardiovascular efficiency in zone 3, lactate tolerance in zone 4, and pure anaerobic capacity in zone 5. The Karvonen method used here improves on simple maximum-heart-rate percentages by incorporating your resting heart rate, which captures your individual cardiovascular fitness. A trained athlete with a low resting heart rate will have different zone boundaries than an untrained person of the same age. Enter your age and morning resting heart rate to get all five zones personalized to your physiology.

How It Works

Step 1 — estimate max heart rate: Max HR = 220 − age. This is the most widely used formula despite having a standard deviation of ±10–12 bpm; a lab or field test provides a more precise figure. Step 2 — calculate Heart Rate Reserve (HRR): HRR = Max HR − resting HR. HRR represents the functional range of your heart rate from rest to maximum effort. Step 3 — apply the Karvonen formula for each zone boundary: Target HR = (HRR × intensity percentage) + resting HR. Zone 1 uses 50–60% of HRR, Zone 2 uses 60–70%, Zone 3 uses 70–80%, Zone 4 uses 80–90%, and Zone 5 uses 90–100%. Because resting HR is added back, zones for a fit person (low resting HR) are lower than for a sedentary person of the same age.

Examples

Healthy Adult

35 years old, resting heart rate 60 bpm.

Result: Max HR 185. Zone 2: ~129–147 bpm. Zone 4: ~166–175 bpm.

Fit Older Adult

50 years old, resting heart rate 55 bpm — well-conditioned.

Result: Max HR 170. Zone 2: ~124–143 bpm. Zones shift lower with age.

Beginner Exerciser

28 years old, higher resting heart rate of 75 bpm.

Result: Max HR 192. Zone 1: ~134–142 bpm — elevated by high resting HR.

Frequently Asked Questions

What zone should I train in most?

Zone 2 (aerobic base) is where most endurance experts recommend spending 70–80% of training time. It builds aerobic capacity with low injury risk. Zone 4–5 should be used sparingly — 1–2 sessions per week.

How is this different from the Target Heart Rate Calculator?

The Target Heart Rate Calculator gives a single target for a chosen intensity. This calculator gives all five zones at once for full training plan visibility.

Is 220 minus age accurate for everyone?

It's an estimate with a standard deviation of ±10–12 bpm. If you've had a lab or field max HR test, use that value for more accurate zones.