Find your ideal training heart rate

What the Target Heart Rate Calculator Does

This Target Heart Rate Calculator estimates the heart rate you should aim for during exercise, based on your age and the workout intensity you choose. Instead of guessing whether you are pushing hard enough or too hard, you get a beats-per-minute (bpm) figure to compare against a heart rate monitor, smartwatch, or a quick pulse check.

It is useful for runners, cyclists, and gym-goers who want to train in a specific zone, as well as beginners building cardiovascular fitness. People recovering from injury or starting exercise after a long break can also use it to keep effort moderate. The result is an estimate for general fitness planning, not medical advice.

How the Target Heart Rate Formula Works

The calculator uses the standard age-based method. First it estimates your maximum heart rate (MHR), then applies your chosen intensity percentage:

THR = (220 - age) x intensity% / 100

The term (220 - age) estimates your maximum heart rate, and the intensity percentage scales that maximum down to a working target. To define a training zone rather than a single number, run the formula twice using the lower and upper intensity of that zone.

• Light / warm-up: 50-60% of MHR
• Fat-burning / moderate: 60-70% of MHR
• Aerobic / cardio: 70-80% of MHR
• Anaerobic / hard: 80-90% of MHR

Worked Example

Suppose you are 40 years old and want to train in the aerobic zone (70-80% intensity).

Start with maximum heart rate: 220 - 40 = 180 bpm. For the lower end, multiply by 70%: 180 x 70 / 100 = 126 bpm. For the upper end, multiply by 80%: 180 x 80 / 100 = 144 bpm.

So a 40-year-old aiming for the aerobic zone should keep their heart rate roughly between 126 and 144 bpm. A single 75% target would be 180 x 75 / 100 = 135 bpm.

Tips and Common Mistakes

The 220-minus-age rule is a simple population average, so individual maximum heart rates can vary by 10-20 bpm in either direction. Treat the numbers as a guide and adjust based on how the effort actually feels.

• Do not rely on a single max-HR formula if you train seriously; a measured test or a more refined equation will be more accurate.
• Check your pulse mid-workout or use a chest-strap monitor, which is generally more accurate than wrist-based optical sensors during intense effort.
• Pair the number with perceived exertion: if you can barely speak, you are likely above your intended zone.
• Beginners should start in the 50-70% range and build gradually rather than chasing high zones.

Factors That Affect Your Result

Several things shift your real heart rate away from the calculated estimate. Caffeine, heat, dehydration, stress, and lack of sleep can all raise it, while improved fitness can lower your resting and working rates over time.

Some medications, particularly beta-blockers, deliberately lower heart rate and make age-based targets unreliable. If you have a heart condition, take such medication, or are pregnant, check with a doctor before setting training targets, since your safe zone may differ from the formula's output.