How hard should your heart work during a run, a bike ride, or a class? A target heart rate gives you a beats-per-minute range to aim for. This calculator turns your age and resting pulse into a training zone with the Karvonen method.
It suits walkers, runners, and gym-goers who wear a watch or check their pulse by hand. You enter two numbers, pick an intensity zone, and read your range right away.
Table of Contents
- What the Calculator Does
- How to Use It, Step by Step
- The Karvonen Formula
- Worked Example
- How to Read the Results
- Choosing a Zone
- Limitations and Assumptions
- FAQs About the Target Heart Rate Calculator
What the Calculator Does
The tool estimates your maximum heart rate, then builds a training range from your heart rate reserve. Results update as you type or change the zone. Five results appear.
- Target Training Heart Rate Zone: the low and high BPM for the zone you picked.
- Max Heart Rate (Estimate: 220 minus Age): 220 minus your age.
- Heart Rate Reserve (HRR): max heart rate minus resting heart rate.
- Light Zone, 60-70% of HRR (Fixed Reference): a fixed range that does not change with the zone menu.
- Tanaka Max HR (208 minus 0.7 x Age, Comparison Only): a second max estimate for comparison.
Two buttons help you save time. Copy Target Zone copies a one-line summary. Reset restores age 30, resting rate 65, and the Aerobic zone.
How to Use It, Step by Step
- Enter Age (Years) as a whole number from 10 to 100. The sample is 30.
- Enter Resting Heart Rate (BPM) as a whole number from 40 to 120. The sample is 65.
- Pick a Target Intensity Zone: Warm-up, Fat Burn, Aerobic, Anaerobic, or Maximum. The sample is Aerobic.
- Read the zone range and the other cards. Use Copy Target Zone to save the text.
A blank, zero, decimal, or out-of-range entry shows a red message and N/A. Your resting rate must also be lower than 220 minus your age. The tool never swaps in a default for you.
Measure your resting rate first thing in the morning, before you get out of bed. Our resting heart rate calculator converts a short pulse count into beats per minute.
The Karvonen Formula
The Karvonen method adds a percentage of your reserve to your resting rate. This makes the zone fit your fitness level better than a plain percent of max. The tool rounds each end to the nearest whole beat.
Reserve (Max - Rest)×Zone %+Resting HR=Target BPM
- Max heart rate = 220 - age.
- Heart rate reserve = max heart rate - resting heart rate.
- Target = reserve × percent + resting heart rate, rounded.
- Tanaka max = 208 - (0.7 × age), rounded. It is displayed but never used in the zones.
Each zone spans ten points of reserve. Warm-up starts at 50 percent and Maximum ends at 100 percent.
Worked Example
Terrence is 45 and has a resting heart rate of 58. His max is 220 - 45 = 175. His reserve is 175 - 58 = 117. For Aerobic, 117 × 0.70 + 58 = 139.9, which rounds to 140. And 117 × 0.80 + 58 = 151.6, which rounds to 152.
| Zone | Percent of Reserve | Terrence's Range |
|---|
| Warm-up | 50 to 60 | 117 - 128 BPM |
| Fat Burn | 60 to 70 | 128 - 140 BPM |
| Aerobic | 70 to 80 | 140 - 152 BPM |
| Anaerobic | 80 to 90 | 152 - 163 BPM |
| Maximum | 90 to 100 | 163 - 175 BPM |
The Tanaka card shows 208 - 31.5 = 176.5, which rounds to 177 BPM. With the sample inputs, the Aerobic zone is 153 - 165 BPM and the max is 190.
How to Read the Results
The big zone range is your working target. Stay between the low and high number for most of the session. Zones touch at the edges, so 140 BPM is the top of Fat Burn and the bottom of Aerobic.
The max heart rate is a population estimate, not a measured value. Individual maximums can differ by ten beats or more. Heart rate reserve shows how much room your heart has between rest and peak effort.
The Light Zone card is a fixed 60 to 70 percent reference. It stays put when you change the menu, so do not mistake it for your chosen zone. The Tanaka number is often higher than 220 minus age for people over 40. If the two values differ, use the zone as a guide and let effort and breathing check it. The heart rate calculator offers another view of the same idea.
Choosing a Zone
Easy zones suit warm-ups, recovery days, and long, steady sessions. Moderate zones build general endurance. Hard zones suit short intervals for people who are already fit.
The Maximum zone reaches your estimated peak and is not meant for long efforts. The tool shows a caution for that zone, for ages over 70, and for a resting rate above 100 BPM. Beginners usually do best in the first three zones. To see how effort links to fitness, try the VO2 max calculator. To estimate energy use, see the calories burned running calculator or the calories burned cycling calculator. Browse more in the health and fitness calculators hub.
Limitations and Assumptions
- The max heart rate formulas are averages. Genetics, fitness, and medicines change real values.
- Beta blockers and some other medicines lower heart rate, so these zones may not apply. The same goes for high blood pressure or a heart condition.
- Every zone uses 220 minus age as the max. The tool never uses a measured max or the Tanaka value.
- The Light Zone card always shows 60 to 70 percent, whatever zone you pick.
- Only ages 10 to 100 and resting rates 40 to 120 are accepted.
- Check with a doctor before hard exercise if you have a heart or other health condition.
FAQs About the Target Heart Rate Calculator
What is a good target heart rate for exercise?
It depends on your goal and fitness. Beginners often start in the lower zones. This tool shows ranges for five zones so you can compare them.
How does the Karvonen formula differ from a simple percent of max?
Karvonen uses your resting rate too. Two people of the same age get different zones if their resting rates differ. A fitter person with a lower resting rate gets a wider reserve.
Why are there two max heart rate numbers?
One is the old 220 minus age rule. The other is the Tanaka equation, from a 2001 review of many studies. It tends to fit older adults better, so the tool shows it as a cross-check.
Is the fat burn zone the best for losing weight?
Not necessarily. The body burns a higher share of fat at lower effort, but total calories matter more. Harder sessions burn more energy per minute. A dietitian can help with weight goals.
How accurate is this calculator?
It gives a reasonable starting range for many healthy adults. It cannot replace a stress test or a doctor's advice. Use perceived effort and breathing as a second check.
Should I be worried if my heart rate goes above the zone?
This tool cannot diagnose anything. Slow down if you feel dizzy, short of breath, or have chest pain. Stop and seek medical help if those signs continue.
This calculator gives general estimates only and is not medical advice. Reviewed for general accuracy by Prof. Dr. Khalil Mudassar, PhD.