Target Heart Rate Calculator: method, checked example and practical limits
Estimate an age-predicted maximum heart rate and Karvonen target zone using resting heart rate. The displayed range is an exercise-planning estimate and does not measure actual maximum heart rate or exercise safety.
Inputs used by this calculator
Target Heart Rate Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Age (years) | 35 | 18 to 100 | Supplies the age (years) quantity used by the published equation or result breakdown. |
| Resting heart rate (bpm) | 65 | 30 to 150 | Supplies the resting heart rate (bpm) quantity used by the published equation or result breakdown. |
| Lower intensity (%) | 50 | 1 to 100 | Supplies the lower intensity (%) quantity used by the published equation or result breakdown. |
| Upper intensity (%) | 85 | 1 to 100 | Supplies the upper intensity (%) quantity used by the published equation or result breakdown. |
Inputs and measurement conventions
The quantities used on this page are Age (years), Resting heart rate (bpm), Lower intensity (%), Upper intensity (%). Start with values for the same situation and read the units attached to each field. The field reference below shows supported choices and numerical limits.
Medication and cardiovascular conditions can change heart-rate response. The resting pulse is required for this reserve-based method.
Method and equation
Estimate maximum heart rate as 208 minus 0.7 times age, then apply the Karvonen heart-rate-reserve equation using resting pulse.
Target Heart Rate Calculator uses the following stated relationship: HRmax=208−0.7×age; target=(HRmax−resting)×intensity+resting. Its assumptions determine which question the answer can resolve.
HRmax=208−0.7×age; target=(HRmax−resting)×intensity+restingWorked calculation with the starting values
Age (years): 35; Resting heart rate (bpm): 65; Lower intensity (%): 50; Upper intensity (%): 85. These starting values give 124 to 166 bpm estimated target zone. The calculation breakdown is Age-predicted maximum: 183.5; Heart-rate reserve: 118.5; Lower target: 124.25; Upper target: 165.725.
A 35-year-old with resting pulse 65 can compare 50% and 85% heart-rate-reserve targets.
Reading the answer
The displayed range is an exercise-planning estimate and does not measure actual maximum heart rate or exercise safety.
Age-predicted maximum: 183.5; Heart-rate reserve: 118.5; Lower target: 124.25; Upper target: 165.725. These intermediate quantities make the stated Target Heart Rate Calculator model inspectable; they should be read together with the main answer rather than treated as independent guarantees.
Common errors and model boundaries
Medication and cardiovascular conditions can change heart-rate response. The resting pulse is required for this reserve-based method.
Age equations are estimates. Medications, symptoms and cardiovascular conditions require individualized exercise advice.
Independent verification and next decision
No. Exercise suitability depends on individual health and may require clinical assessment or a supervised test.
For the Target Heart Rate Calculator method, compare HRmax=208−0.7×age; target=(HRmax−resting)×intensity+resting with the starting inputs and the calculation table. The linked Tanaka, Monahan and Seals: age-predicted maximum heart rate and American Heart Association: target heart rates references identify the relevant definitions, conventions or domain limitations. Retain intermediate precision when comparing a manually worked answer.
Target Heart Rate Calculator worked-example ledger
| Quantity | Example value | Role |
|---|---|---|
| Age (years) | 35 | Entered assumption |
| Resting heart rate (bpm) | 65 | Entered assumption |
| Lower intensity (%) | 50 | Entered assumption |
| Upper intensity (%) | 85 | Entered assumption |
| Main answer | 124 to 166 bpm estimated target zone | Calculated from the starting inputs |
| Age-predicted maximum | 183.5 | Intermediate or contextual output |
| Heart-rate reserve | 118.5 | Intermediate or contextual output |
| Lower target | 124.25 | Intermediate or contextual output |
| Upper target | 165.725 | Intermediate or contextual output |
Frequently asked questions
Can everyone safely train at the displayed zone?
No. Exercise suitability depends on individual health and may require clinical assessment or a supervised test.
Which relationship does the Target Heart Rate Calculator use?
Estimate maximum heart rate as 208 minus 0.7 times age, then apply the Karvonen heart-rate-reserve equation using resting pulse. The displayed relationship is HRmax=208−0.7×age; target=(HRmax−resting)×intensity+resting.
What do the starting values produce in the Target Heart Rate Calculator?
Age (years): 35; Resting heart rate (bpm): 65; Lower intensity (%): 50; Upper intensity (%): 85. These starting values give 124 to 166 bpm estimated target zone. The calculation breakdown is Age-predicted maximum: 183.5; Heart-rate reserve: 118.5; Lower target: 124.25; Upper target: 165.725.
How should I interpret this Target Heart Rate Calculator answer?
The displayed range is an exercise-planning estimate and does not measure actual maximum heart rate or exercise safety.
Which input mistake most affects the Target Heart Rate Calculator?
Medication and cardiovascular conditions can change heart-rate response. The resting pulse is required for this reserve-based method.
What is outside this Target Heart Rate Calculator model?
Age equations are estimates. Medications, symptoms and cardiovascular conditions require individualized exercise advice.
What to keep in mind
Age equations are estimates. Medications, symptoms and cardiovascular conditions require individualized exercise advice.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.