Target Heart Rate CalculatorFree online fitness & health calculator — instant results, no sign-up
Training heart-rate zones by age (Karvonen).
For general information only. This is not medical advice, diagnosis, dosing guidance or a treatment recommendation. Talk to a doctor or other qualified health professional about your health, pregnancy, or diet.
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About the Target Heart Rate Calculator
The Target Heart Rate Calculator determines your maximum heart rate and cardiovascular training zones using the Tanaka and Karvonen formulas. Runners, cyclists, and fitness enthusiasts use these zones to tailor workout intensity for endurance, aerobic capacity, or high-intensity intervals.
- Age
- Your current age in years, typically ranging from 10 to 100.
- Resting heart rate
- Your baseline pulse at rest in beats per minute (bpm), usually measured right after waking up, typically between 40 and 100 bpm.
Formula and method
HRmax = 208 - (0.7 × Age) THR = HRrest + (HRmax - HRrest) × Intensity
- AgeAge of the user in years
- HRmaxEstimated maximum heart rate in beats per minute (bpm)
- HRrestResting heart rate in beats per minute (bpm)
- IntensityTarget exercise intensity percentage expressed as a decimal (e.g., 0.50, 0.70, 0.85)
- THRTarget heart rate at a given intensity
The tool first calculates maximum heart rate using Tanaka's equation: 208 - 0.7 × Age. It then calculates the heart rate reserve (HRmax - HRrest) and adds resting heart rate back to the scaled reserve at 50%, 70%, and 85% intensity levels using the Karvonen method. All final heart rate boundaries are rounded to the nearest integer.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Age30 years
- Resting heart rate65 bpm
Results
- Max heart rate187 bpm
- Moderate (50–70%)126–150 bpm
- Vigorous (70–85%)150–169 bpm
How to use the Target Heart Rate Calculator
- 1Multiply your age by 0.7 and subtract that product from 208 to determine your estimated maximum heart rate.
- 2Subtract your resting heart rate from your estimated maximum heart rate to find your heart rate reserve (HRR).
- 3Multiply the heart rate reserve by each target percentage (50%, 70%, and 85%) and add your resting heart rate back to each.
- 4Round each resulting boundary to the nearest whole beat per minute to establish moderate (50–70%) and vigorous (70–85%) zones.
Reading your result
The Moderate zone (50–70% HRR) represents steady-state aerobic activity such as brisk walking or easy jogging, ideal for building base endurance. The Vigorous zone (70–85% HRR) represents higher-intensity training where breathing is labored, helping improve aerobic capacity and lactate threshold. Exercising below 50% is generally active recovery, while exceeding 85% enters near-maximal anaerobic effort.
Limitations
The Tanaka equation estimates maximum heart rate based on population averages and can deviate by 10 to 15 bpm for an individual. It does not account for cardiovascular medications (such as beta-blockers) that suppress heart rate response, ambient temperature, dehydration, or variations in daily fatigue.
Common questions
Why does this calculator use 208 - 0.7 × Age instead of 220 - Age?+
The formula 208 - 0.7 × Age (developed by Tanaka et al.) is widely supported in exercise physiology as a more accurate estimate of maximum heart rate across varying ages than the traditional Fox formula (220 - Age), which tends to underestimate max heart rate in older adults.
What is the benefit of the Karvonen method over standard percentage of max heart rate?+
The Karvonen method factors in your resting heart rate by calculating heart rate reserve. This personalizes target zones to your baseline cardiovascular fitness, whereas a simple percentage of max heart rate treats everyone of the same age identically.
When is the best time to measure resting heart rate?+
Measure your resting heart rate in the morning right after waking up, before getting out of bed, drinking coffee, or checking stressful notifications. Take the average over several consecutive mornings for the most reliable number.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
Further reading
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Results are estimates for informational purposes and are not financial, medical or legal advice.