❤️ Heart Rate Zone Calculator

Estimate your maximum heart rate and the training zones — fat burn, cardio, and peak — that go with it, using the standard 220-minus-age formula, with an optional resting-heart-rate (Karvonen) adjustment.

Age (years)

Resting Heart Rate (bpm, optional)

Two ways to slice the same five zones

Maximum heart rate comes from the Fox formula, 220 minus age. What happens next depends on whether you fill in the resting heart rate box:

max HR = 220 - age
plain:    zone bpm = max HR × percentage
Karvonen: zone bpm = (max HR - resting HR) × percentage + resting HR

At 30 your max is 190 bpm, and zone 2 - the 60-70% "fat burn" band - runs 114 to 133 bpm. Add a resting rate of 65 and Karvonen works from a reserve of 125, putting the same zone at 140 to 153 bpm. Karvonen counts from where your heart already idles, so trust it if you know your true resting rate.

What each zone is for

Zones 1-2 (50-70%) conversational pace, where the bulk of endurance training should live and where most people go too hard.
Zone 3 (70-80%) aerobic work, talking in short sentences.
Zones 4-5 (80-100%) intervals - minutes, not hours.

Take resting heart rate on waking, averaged over three mornings. A wrist optical sensor drifts badly above zone 3, so use a chest strap if the upper zones matter.

220 minus age is a population average with a spread of about ±10-12 bpm, so your real maximum could be 180 or 200, and past about 40 the alternative 208 - (0.7 × age) fits better. Beta blockers make all of these formulas meaningless - ask your doctor for your own numbers.

Frequently asked questions

What should my heart rate be when running?

For steady running, zone 2 to low zone 3 - about 60-80% of maximum, or roughly 114-152 bpm at age 30. Above that is interval work, not base mileage.

Is the fat burning zone real?

The share of energy from fat is highest at low intensity, but total calories burned are lower, so harder work burns more fat per session in absolute terms. The zone is a pacing label, not a shortcut.

How do I find my actual maximum heart rate?

Only a supervised graded exercise test measures it properly. Hard hill repeats with a chest strap get close, but do not chase the number without medical clearance.