Max Heart Rate Calculator

Your maximum heart rate drops every birthday. The candles are doing it on purpose.

Use this free max heart rate calculator to estimate your maximum heart rate (MHR) and your fat-burning zone in beats per minute. Enter your age and get both numbers — the ceiling your heart can theoretically reach, and the range where moderate cardio actually lives.

Heart rate zones are how you stop guessing during cardio. Too easy and nothing adapts; too hard and you cannot sustain it long enough to matter. The zone is the difference between exercising and simply being tired.

What This Max Heart Rate Calculator Does

Estimates maximum heart rate with the classic 220 − age formula
Calculates the fat-burn zone at 60–70% of maximum
Gives you target numbers for a watch, chest strap, or treadmill handle
Shows all five training zones in the notes so you can build a full plan

How to Use the Max Heart Rate Calculator

Inputs:

Age — in years

Steps:

Enter your age
Click Calculate for max heart rate and the fat-burn range
Use the zone table below to find the range for your session — easy, tempo, or intervals
Compare against what your watch reports during real efforts; if you consistently exceed the "max," your real max is higher than the formula

How the Calculation Works

Max HR = 220 − Age Fat Burn = Max HR × 0.60 → 0.70

Zone 1 (50–60%) recovery · Zone 2 (60–70%) fat burn / base endurance · Zone 3 (70–80%) aerobic · Zone 4 (80–90%) threshold · Zone 5 (90–100%) VO₂ max
The Tanaka formula (208 − 0.7 × age) is more accurate for adults over 40; at 50 it gives 173 instead of 170
Individual maximums vary by ±10–12 bpm from any formula — two 40-year-olds can genuinely differ by 25 bpm
The "fat burn" label is about fuel percentage, not total fat burned. Harder sessions burn more total calories and more total fat

Worked Example: 38 years old

Max HR = 220 − 38 = 182 bpm
Fat burn zone = 182 × 0.60 to 182 × 0.70 = 109–127 bpm
Aerobic zone (70–80%) = 127–146 bpm · Threshold (80–90%) = 146–164 bpm
Tanaka check: 208 − 0.7 × 38 = 181 bpm. Close enough that the argument is academic at 38 and matters at 60.

Tips (From People Who Have Made These Mistakes)

Most endurance gains come from lots of Zone 2 work plus a little Zone 4 — not from living permanently in the middle
Talk test, no strap needed: Zone 2 means you can hold a conversation; Zone 4 means short sentences only
A resting heart rate of 50–70 is typical, lower with training. A rising resting rate over several days usually means fatigue or illness
Beta blockers and other medications lower heart rate directly, which makes formula zones meaningless. Use perceived effort instead

Frequently Asked Questions

What is my maximum heart rate?

Estimate it as 220 minus your age: 185 bpm at 35, 170 at 50. It is a population average with roughly ±10 bpm of individual variation, so treat it as a reference point.

What is the fat burning heart rate zone?

60–70% of maximum — 111–130 bpm for a 35-year-old. At that intensity a higher share of calories comes from fat, though higher intensities burn more fat in total because they burn more of everything.

Is 220 minus age accurate?

It is accurate enough for general fitness and noticeably off for older and very fit people. 208 − 0.7 × age predicts better after 40. A supervised max test is the only precise answer.

What heart rate should I exercise at?

For general health, 60–80% of max for 30+ minutes most days. Improving fitness means mostly easy Zone 2 with occasional hard intervals at 85–95%.

Is a high heart rate during exercise dangerous?

Briefly reaching near-maximum is normal for healthy people during hard effort. Chest pain, dizziness, or irregular rhythm is not — stop and get checked. Over 40, sedentary, or with heart risk factors, talk to a doctor before starting intense training.

Mini Roast Disclaimer

We roast the number, not you. Your heart has beaten roughly a billion times without a single complaint. Be more like your heart.

Reality Check

Every age-based formula is an estimate with wide individual variation, and medication, caffeine, heat, dehydration, and stress all shift heart rate on the day. If you have a cardiac condition or take rate-affecting medication, get your zones from a clinician rather than subtraction.

Max Heart Rate Calculator

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