Target Heart Rate Calculator

How the Target Heart Rate Calculator works

Enter a maximum heart rate in beats per minute and pick an intensity band. The tool multiplies the MHR by the midpoint of that band to give a single target, and also shows the band itself in beats per minute so you can see the room either side. The three bands are Light at 50 to 60% of MHR, Moderate at 60 to 80%, and Vigorous at 80 to 90%.

The formula

Target HR = Max HR × (intensity % ÷ 100)

The percentage used is the midpoint of the selected band: 55% for Light, 70% for Moderate, 85% for Vigorous. Working the default, an MHR of 190 bpm at Moderate gives 190 × 0.70 = 133 bpm, sitting inside a band that runs 190 × 0.60 = 114 bpm to 190 × 0.80 = 152 bpm. Light spans 95 to 114 bpm with a midpoint of 105, and Vigorous spans 152 to 171 bpm with a midpoint of 162. Band boundaries differ between published schemes, so treat the edges as soft and the numbers either side of them as describing much the same effort.

Why this method is the crude one

Multiplying MHR by a percentage ignores resting heart rate entirely, and that omission is not small. Take the same 190 bpm maximum with a resting rate of 60. The percentage-of-MHR method puts 70% at 133 bpm. The heart rate reserve method, which works from the 130 bpm gap between rest and maximum, puts 70% at 0.70 × 130 + 60 = 151 bpm. Eighteen beats apart, from the same maximum and the same nominal percentage. The reserve figure is the better-grounded of the two: percentage of heart rate reserve corresponds to percentage of VO₂ reserve rather than to percentage of VO₂max (Swain and Leutholtz, 1997; Swain et al., 1998). Use this tool when you do not have a resting heart rate, and the Karvonen calculator on this site when you do.

Where this method is most accurate

Everything here rests on the maximum heart rate you feed in. A graded exercise test measures it; an age-prediction equation estimates it with a wide individual spread, which is why the Tanaka equation is usually preferred over 220 minus age for population work (Tanaka et al., 2001). The percentage approach also assumes a broadly linear relationship between intensity and heart rate, which holds well enough for steady-state aerobic work in healthy adults and less well at the extremes. It does not account for medication, heat, altitude, dehydration, cardiac drift over a long session, or the fitness adaptations that shift the whole response curve (Garber et al., 2011).

What this tool does not do

It is a calculator, not a training prescription. It does not recommend session durations, frequencies, or progressions. It does not measure heart rate, assess cardiovascular health, or substitute for clinical exercise testing. It does not model individual autonomic variation, cardiac drift, or sport-specific demands. For zones tied more closely to physiology, heart rate reserve or lactate-threshold testing gives a better answer than a percentage of maximum.

Disclaimer

This tool is for educational and informational purposes only. It does not constitute medical, clinical, or training advice. Consult a physician before beginning any exercise program, especially if cardiovascular conditions, symptoms, or risk factors are present. All outputs are estimates derived from generalised formulas and may not reflect individual physiology.