Health & Fitness

Target Heart Rate Calculator

This calculator uses the Karvonen (heart-rate reserve) method. Enter your age and resting heart rate and it returns the low and high bounds of a 50 to 85 percent training zone in beats per minute.

What this calculator does

The Target Heart Rate Calculator estimates your result instantly from the values you enter, using standard health & fitness formulas. This calculator uses the Karvonen (heart-rate reserve) method. Enter your age and resting heart rate and it returns the low and high bounds of a 50 to 85 percent training zone in beats per minute. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.

Target Heart Rate Calculator

Result

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Zone Low (bpm)
—
Zone High (bpm)

About Target Heart Rate Calculator

The Target Heart Rate Calculator applies the Karvonen formula, which works from your heart-rate reserve rather than max heart rate alone. It first estimates maximum HR as 220 minus age, subtracts your resting heart rate to get the reserve, then reports the beats-per-minute bounds of a 50 to 85 percent zone. Use it to set a sensible aerobic training range.

Formula & Mathematical Calculation

Zone Low (bpm) = f(Age (years), Resting HR (bpm))

Calculated according to standard health formulas implemented in the calculator core.

Calculation Example

For an age of 30 and a resting HR of 65 bpm: max HR is 220 - 30 = 190, and reserve is 190 - 65 = 125. The tool shows Zone Low = 128 bpm and Zone High = 171 bpm, with the note: "Karvonen 50-85 percent training zone: 128 to 171 bpm."

Key Benefits

  • Uses the Karvonen heart-rate reserve method, which factors in your resting heart rate rather than age alone
  • Returns both the lower (50 percent) and upper (85 percent) bounds of the training zone in bpm
  • Only needs two inputs, age and resting heart rate, and shows the zone instantly

How to Use this Calculator

  1. Enter your age
    Type your age in years into the Age field (for example 30).
  2. Enter your resting heart rate
    Type your resting HR in beats per minute into the Resting HR field (for example 65).
  3. Calculate and read the zone
    Click Calculate and read the Zone Low (bpm) and Zone High (bpm) result boxes.

Assumptions & Limitations

What the calculation assumes

  • Every value you enter is treated as an exact, known amount.
  • Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
  • Results use standard published formulas and account only for the values entered above.
  • Rounding is applied for display; the underlying calculation uses your full precision.
  • Results are returned in the same units you enter, unless the tool states the output unit.

What it does not cover

  • Target Heart Rate Calculator produces a calculated result for reference and learning, not a certified or official measurement.
  • Real-world outcomes differ when tolerances, rounding rules or local standards apply.
  • Definitions and standards vary by region and change over time; verify the convention that applies to your case.
  • Figures are only as accurate as the inputs you supply — check them before acting on the result.
  • For work where the result carries real consequences, confirm it against an authoritative source.

Frequently Asked Questions

It uses the Karvonen formula: max HR is estimated as 220 minus age, resting HR is subtracted to get heart-rate reserve, and the reserve is scaled to 50 percent for the low bound and 85 percent for the high bound, then resting HR is added back.

The Karvonen method uses heart-rate reserve, which is max HR minus resting HR. A lower resting heart rate shifts the target zone, so resting HR is a required input here.

The calculator estimates maximum heart rate as 220 minus your age. It does not measure your true max HR; that would require a test.

Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.