MultiConvers

Target Heart Rate Calculator

Estimate maximum heart rate with Tanaka (208 − 0.7×age) and five training zones. Leave resting HR blank for percent-of-max zones; enter it to switch the same intensities to Karvonen heart-rate reserve. This is not 220 minus age, and it is not a lab test.

How to use

  1. Enter age in years. HRmax is 208 − 0.7×age (Tanaka 2001). Age 30 is 187 bpm.
  2. Optionally enter resting heart rate in bpm if you want Karvonen zones instead of plain %HRmax.
  3. Read estimated HRmax and the five bands (50–60% through 90–100%). Zone 3 at age 30 without rest is about 131–150 bpm.
  4. Do not treat predicted max as measured max. Stop if you feel unwell. This is not a training prescription.

How it works

Tanaka, Monahan and Seals (2001) fitted HRmax as 208 − 0.7×age on adult data. That line replaced the folklore 220 − age for most teaching charts, which is why this page never computes 220 − age. Age 40 is 208 − 28 = 180 bpm predicted max. Individual error around any age formula is large; a lab or field max test can sit well above or below the line.

Without a resting pulse, zones are simple percentages of that predicted max: 50–60%, 60–70%, 70–80%, 80–90%, 90–100%. With a resting HR, Karvonen scales each intensity through reserve: (HRmax − rest) × intensity + rest. A high resting pulse lifts the whole set of zones; a low resting pulse lowers them. The optional field is the only switch between the two methods.

Predicted max is not your measured max. Beta blockers, illness, heat and caffeine all move real heart rate. The calculator does not know medication. It also does not know whether you measured rest sitting for five minutes or standing in a queue.

Pace and MET calories do not use heart rate. This page does not convert a zone into a running pace. BMR and TDEE are energy equations, not pulse.

Not medical advice. People with a heart condition need clinician limits, not a website zone table. Stop if you feel unwell.

Formula

HRmax = 208 − 0.7 × age   (Tanaka)
%HRmax zone: HRmax × intensity
Karvonen: (HRmax − HRrest) × intensity + HRrest

Worked examples

  • Tanaka at age 30

    age 30, no resting HR → HRmax 187 bpm; zone 3 ≈ 131–150 bpm

Useful notes

  • 220 − age is mentioned only as the older rule of thumb this page does not use.
  • Resting HR is optional; when present, zones use Karvonen reserve.
  • Not medical advice. Stop if you feel unwell.

FAQ

Why not 220 minus age?

That rule is a rough average. Tanaka’s 208 − 0.7×age is a later published fit and is what this page uses.

What does Karvonen add?

It scales intensity through heart-rate reserve (max minus rest), so zones sit above your resting pulse.

Should I train at these numbers?

They are estimates. A clinician or coach sets limits if you have a heart condition.

Is predicted HRmax the same as a treadmill max test?

No. Tanaka is an age line. A measured max can differ by a wide margin.

What if I leave resting HR blank?

Zones are percentages of Tanaka HRmax only. Karvonen is used only when you enter a resting pulse.

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