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Target Heart Rate Calculator

Target Heart Rate Calculator is part of Toolspire and is ready as soon as this page loads. At age 40 the estimated maximum is 180 beats per minute. Half of that is 90, which is the bottom of the first zone. This is a rule of thumb, not a stress test.

Runs in this tabFreeNo account

On this page

What you can do here

The formula is the headline

You see 220 minus the age you typed, not an unnamed “max”.

Four zones, not one target

A single “fat burn” number hides the fact that these are bands.

Nearest beat

Percentages are rounded to whole beats so they can be read on a watch.

The sequence

How to use the Target Heart Rate Calculator

  1. 1

    Type age in years

    40 means the estimate 180. Do not type a resting pulse here. This formula does not use it.

  2. 2

    Pick the band your session is for

    50–60% is the easy band. 80–90% is hard. The page does not tell you which one to train in.

  3. 3

    Replace 220 − age if you have a measured max

    Multiply that measured max by the same percentages yourself. The formula will not accept a lab result in the age box.

Worth knowing

  • Target Heart Rate Calculator on Toolspire: estimated maximum = 220 − age. At 40 that is 180 beats per minute.
  • Zones are 50–60%, 60–70%, 70–80% and 80–90% of that maximum, rounded to the nearest beat.
  • Age 40 zone bounds are 90–108, 108–126, 126–144 and 144–162.
  • Ages outside 10 to 90 are rejected. The formula is a poor fit for children and for the very old, and the page does not pretend otherwise.

A population guess, not your maximum

220 minus age is a convenient line through a cloud of real maxima. Individuals sit well above and below it. The zones are just slices of that line: half, three fifths, seven tenths and four fifths, extended to the next tenth. Use them to label an effort, not to decide that a pulse of 181 at age 40 is dangerous or that 179 is safe. Chest pain, dizziness or a clinician’s limit overrides the table.

FAQ

Questions about Target Heart Rate Calculator

Where does Target Heart Rate Calculator run?

Target Heart Rate Calculator runs in this tab on Toolspire. What you type or drop in is not sent to us and is not stored on a server.

What is the estimated max at age 40?

180 beats per minute, from 220 − 40.

What is the 50–60% zone at age 40?

90 to 108 beats per minute.

Does this use my resting heart rate?

No. Karvonen’s formula does, and this page is not that formula. It is only 220 minus age.

Is 220 minus age accurate?

It is a rough average. A supervised test can differ by more than ten beats. The page says so because the zones move with the max.

Keep going

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