This heart rate calculator figures the ideal and average target heart rate, upper & lower limits, maximum and heart rate reserve in bpm. You can read more about these measurements below the form.

## How does this heart rate calculator function?

This tool uses the Karvonen formula and some others that are described below to estimate different personalized measures of the heart rate based on your age, resting heart rate (RHR) and intensity level expressed as a percentage. The maximum heart rate formulas used are: Tanaka, Monahan & Seals max heart rate formula, Haskell and Fox max heart rate formula, Robergs and Landwehr max heart rate formula.

The maximum heart rate can de discovered by using one of these three formulas:

- Tanaka, Monahan & Seals formula = 208 − (0.7 * Your age in years)
- Haskell and Fox formula = 220 − Your age in years
- Robergs and Landwehr formula= 205.8 – (0.685 * Your age in years)

By the Karvonen method this application estimates ideal target heart rate and the range of the target heart rate. Please note that in general the human heart rate ranges between 60 and 100 beats per minute (bpm).

Here are the steps performed by the algorithm of this heart rate calculator:

1. Calculating Maximum heart rate by using a specific max heart rate formula (one of the three above)

2. Calculating Heart Rate Reserve (HRR) = Maximum heart rate – Resting heart rate value.

3. Calculating Min. of the target heart rate for the target heart rate range = Heart rate reserve * 0.6.

4. Calculating Max. of the target heart rate for the target heart rate range = Heart rate reserve * 0.8.

5. Calculating the Average Target Heart Rate = (Min. of the target heart rate + Max. of the target heart rate)/2.

6. Calculating the Ideal Target Heart Rate at the level of intensity specified = (Heart Rate Reserve × Intensity percent) + Resting Heart Rate.

Please note that the ideal target heart rate values displayed are an estimate so they should be considered with reservation. The heart rates differ from one person to another so the estimations presented by this tool do not pretend to be 100% accurate.

## What does the heart rate show us?

While the Karvonen formula is usually used in connection to cardiovascular exercise, the other determinations can prove to be important signs of our health. For instance, maximum heart rates can show how hard one’s heart can work during physical exertion. It is usually determined by genetic factors and it also diminishes with age and training doesn’t seem to have any impact on it.

## References

1) Kolata G. (2001) 'Maximum' Heart Rate Theory Is Challenged. New York Times.

2) Robergs R, Landwehr R. (2002) The Surprising History of the 'HRmax=220-age' Equation (PDF) Journal of Exercise Physiology 5 (2): 1–10.

3) Tanaka H, Monahan KD, Seals DR. (2001) Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 37(1):153-6.

09 Jan, 2015