Target Heart Rate Calculator

How to use it

Enter your age.
Optionally add your resting heart rate.
Choose a maximum heart rate formula or enter your measured max.
Read your maximum heart rate and the five zones in beats per minute.

Estimating your maximum heart rate

Your maximum heart rate (HRmax) is the highest rate your heart reaches during all-out effort. You can pick one of two formulas, or enter a value you measured in a hard test:

Tanaka: 208 − 0.7 × age. Based on a large meta-analysis, generally more accurate, especially for older adults.
Classic: 220 − age. Simple and widely used, but it tends to underestimate HRmax in older people.

At age 40, Tanaka gives 180 bpm and the classic formula also gives 180 bpm; at 60, Tanaka gives 166 bpm versus 160 bpm. Individual values can differ by 10–12 bpm either way, so a measured maximum is best if you have one.

Percentage of max vs. Karvonen

Without a resting heart rate, zones are simple percentages of your maximum: Zone 2 at 60–70% of 180 bpm is 108–126 bpm.

With a resting heart rate, the calculator uses the Karvonen formula, which works from your heart rate reserve (HRR = max − resting):

Target = resting + (max − resting) × intensity %

Example: age 40, max 180, resting 60. HRR = 120. Zone 2 (60–70%) = 60 + 120 × 0.6 to 60 + 120 × 0.7 = 132–144 bpm. Karvonen zones are higher and usually fit fit people better, because they account for a low resting rate. Measure your resting heart rate in the morning before you get up.

The five training zones

Zone	Intensity	What it feels like and trains
1 – Recovery	50–60%	Very easy; warm-ups, cool-downs, recovery days
2 – Base endurance	60–70%	Comfortable, you can talk in full sentences; builds aerobic base and fat use
3 – Aerobic	70–80%	Moderate to hard; steady runs and rides
4 – Threshold	80–90%	Hard, short phrases only; raises your lactate threshold
5 – Maximum	90–100%	All-out, only sustainable for short intervals

What guidelines recommend

For general health, U.S. physical activity guidelines recommend at least 150 minutes a week of moderate-intensity activity or 75 minutes of vigorous activity, plus muscle-strengthening work twice a week. Moderate intensity roughly corresponds to 50–70% of maximum heart rate and vigorous intensity to 70–85%. Most endurance coaches suggest doing the bulk of training in Zones 1–2 and a smaller share at higher intensity.

Safety and medications

Heart rate formulas are population averages. Some medications, especially beta blockers, lower your heart rate and make these zones inaccurate. If you have heart disease, high blood pressure, are starting exercise after a long break, or get chest pain, dizziness or unusual shortness of breath during exercise, talk to your doctor about safe training intensities.

This calculator is informational and not medical advice. Your data is processed in your browser only.

Frequently asked questions

What is my target heart rate?

For moderate exercise it's roughly 50–70% of your maximum heart rate; for vigorous exercise, about 70–85%. The calculator shows the exact numbers for your age.

How do I calculate my maximum heart rate?

Common estimates are 220 − age or the Tanaka formula, 208 − 0.7 × age. A supervised exercise test gives the most accurate value.

What is zone 2 heart rate?

Zone 2 is 60–70% of maximum heart rate (or of heart rate reserve with Karvonen), an easy pace where you can still hold a conversation.

What is a normal resting heart rate?

For most adults it's between 60 and 100 beats per minute. Well-trained athletes can be lower.

Why are my Karvonen zones higher?

Karvonen adds your resting heart rate back in, so zones start from a higher floor. They're usually more accurate for people with a low resting rate.

Sources

Last reviewed: November 14, 2026 · Kitpebble editorial team

Change log

November 14, 2026: Sources expanded; FAQ and content reviewed.

For general information only; not medical advice or a diagnosis. How we write and review our pages

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