Heart Rate Reserve Calculator

Build workout zones from resting and maximum pulse. Adjust formulas, intensities, and custom inputs easily. Train with clearer targets for safer, stronger endurance sessions.

Calculator Form

Use this only when you know your tested maximum.

Example Data Table

Age Resting HR Method Intensity Range Estimated Max HR HRR Target Zone
35 60 bpm Tanaka 60% - 80% 183.5 bpm 123.5 bpm 134 - 159 bpm
42 58 bpm Fox 50% - 70% 178 bpm 120 bpm 118 - 142 bpm
28 54 bpm Gellish 70% - 90% 187.4 bpm 133.4 bpm 147 - 174 bpm

Formula Used

Heart Rate Reserve: HRR = Maximum Heart Rate - Resting Heart Rate

Target Heart Rate: Target HR = Resting Heart Rate + (Intensity % × HRR)

Fox Method: Maximum Heart Rate = 220 - age

Tanaka Method: Maximum Heart Rate = 208 - (0.7 × age)

Gellish Method: Maximum Heart Rate = 207 - (0.7 × age)

Current Intensity Estimate: Intensity % = ((Current HR - Resting HR) ÷ HRR) × 100

The calculator applies the Karvonen approach to convert reserve percentage into a target pulse range. This usually gives more personalized exercise zones than using a flat percentage of maximum heart rate alone.

How to Use This Calculator

  1. Enter your age and resting heart rate. Measure resting pulse after sitting quietly.
  2. Choose a maximum heart rate method. Use the custom option only if you know your tested maximum.
  3. Set your minimum and maximum intensity percentages for the workout range you want to plan.
  4. Choose a zone step size to split the range into clear training bands.
  5. Optionally enter your current heart rate to estimate where you sit inside the selected range.
  6. Press Calculate to show targets above the form, then export the zone table as CSV or PDF.

Frequently Asked Questions

1. What is heart rate reserve?

Heart rate reserve is the difference between your maximum heart rate and resting heart rate. It helps set exercise targets that better reflect your current fitness than simple maximum heart rate percentages.

2. Why use heart rate reserve instead of maximum heart rate alone?

It includes resting pulse, so the target range adjusts to your baseline condition. That makes training zones more personalized, especially when two people have the same age but different resting heart rates.

3. Which maximum heart rate formula is best?

No single formula is perfect for everyone. Tanaka and Gellish are common estimates, while custom values work best when you have results from testing or professional evaluation.

4. What intensity range suits easy cardio?

Many people use about 50% to 70% of heart rate reserve for easier aerobic work. Your actual target may vary with experience, goals, medication, and health status.

5. Can I use this calculator for interval training?

Yes. You can set higher upper intensity values and use smaller step sizes. That helps map recovery, working, threshold, and peak ranges inside one workout plan.

6. Why does my current heart rate fall outside the selected range?

Your current heart rate may reflect warmup, fatigue, dehydration, heat, stress, caffeine, or recovery. The calculator simply compares that reading against the range you selected.

7. Is a custom maximum heart rate better?

A tested value can be better because it reflects your actual response rather than a population estimate. Only use a custom figure when it comes from reliable testing.

8. Should this replace medical advice?

No. This tool supports exercise planning, not diagnosis or treatment. If you have symptoms, heart conditions, or take medication affecting pulse, ask a qualified clinician first.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.