Complete guide
Target Heart Rate Calculator: formula, worked example and interpretation
Estimate an age-predicted maximum heart rate and Karvonen target zone using resting heart rate. Enter the known values and the result updates instantly with an auditable breakdown.
What the Target Heart Rate Calculator answers
Estimate an age-predicted maximum heart rate and Karvonen target zone using resting heart rate.
Use the breakdown to compare the result with the source values before making a decision.
Formula and variables
The calculation uses HRmax=208−0.7×age; target=(HRmax−resting)×intensity+resting. Every variable comes directly from a labeled field.
HRmax=208−0.7×age; target=(HRmax−resting)×intensity+restingWorked example
A 35-year-old with resting pulse 65 can compare 50% and 85% heart-rate-reserve targets.
Changing any field recalculates the result immediately, so nearby scenarios can be compared without reloading the page.
How to use the result
Treat the result as a planning value and compare it with the detailed rows shown beside it.
Keep units and time periods consistent. Use the share or PDF action to preserve the exact assumptions.
Assumptions and scope
Age equations are estimates. Medications, symptoms and cardiovascular conditions require individualized exercise advice.
The calculator exposes its assumptions instead of filling missing facts with hidden estimates.
Accuracy checks
Confirm the units, dates, rates and source figures before relying on the output.
Round only the displayed answer; Calculator24 keeps full JavaScript precision for intermediate arithmetic and exported values.
Input and output checklist
| Item | What to enter or review |
|---|---|
| Inputs | Age (years), Resting heart rate (bpm), Lower intensity (%), Upper intensity (%) |
| Equation | HRmax=208−0.7×age; target=(HRmax−resting)×intensity+resting |
| Example | A 35-year-old with resting pulse 65 can compare 50% and 85% heart-rate-reserve targets. |
| Limit | Age equations are estimates. Medications, symptoms and cardiovascular conditions require individualized exercise advice. |
Frequently asked questions
What does this Target Heart Rate Calculator calculate?
Estimate an age-predicted maximum heart rate and Karvonen target zone using resting heart rate.
Which formula does it use?
HRmax=208−0.7×age; target=(HRmax−resting)×intensity+resting
Does the result update while I type?
Yes. Valid changes recalculate after a short delay and the previous result is not substituted for invalid input.
Which assumptions should I check?
Check units, rates, dates and every source value shown in the form.
Is the result exact?
Age equations are estimates. Medications, symptoms and cardiovascular conditions require individualized exercise advice.
Can I save or share the calculation?
Yes. Copy, Share, WhatsApp, PDF/Print, CSV, comparison and parameterized-link actions are available.
What to keep in mind
Age equations are estimates. Medications, symptoms and cardiovascular conditions require individualized exercise advice.
Results display up to 8 decimal places; exported numbers preserve calculation precision. This is a calculation summary, not an official certificate.