Target Heart Rate Calculator

Maximum heart rate

Your maximum heart rate is the highest number of beats per minute your heart can reach during hard exercise. Two common estimates are:

Standard: Max HR = 220 − Age

Tanaka: Max HR = 208 − (0.7 × Age)

For a 40-year-old, both give 180 beats per minute (bpm). At age 60 the standard formula gives 160 bpm and the Tanaka formula gives 166 bpm. The most accurate figure is one you measure yourself during a hard effort.

Target heart rate zones

Heart rate zones are ranges of effort, written as a share of your maximum:

• Moderate intensity: 50% to 70% of your maximum, where you can talk but not sing
• Vigorous intensity: 70% to 85% of your maximum, where you can say only a few words at a time

Target heart rate = Max HR × Intensity %

For a 40-year-old with a maximum of 180 bpm, the moderate zone is 90 to 126 bpm and the vigorous zone is 126 to 153 bpm.

The Karvonen formula

The Karvonen method adds your resting heart rate to personalize the zones. It uses your heart rate reserve (HRR), the gap between your maximum and resting rates:

HRR = Max HR − Resting HR

Target heart rate = (HRR × Intensity %) + Resting HR

If that 40-year-old has a resting rate of 60 bpm, the reserve is 120. The moderate zone becomes (120 × 50%) + 60 = 120 bpm up to (120 × 70%) + 60 = 144 bpm, and the vigorous zone runs from 144 to 162 bpm. Fitter people with lower resting rates get higher zones than the simple percentage method gives.

The five training zones

• Zone 1 (50 to 60%): warm-up, cool-down and recovery
• Zone 2 (60 to 70%): easy endurance work, where the body uses a high share of fat for fuel
• Zone 3 (70 to 80%): steady aerobic training that builds stamina
• Zone 4 (80 to 90%): hard efforts that raise your speed and threshold
• Zone 5 (90 to 100%): all-out sprints and short intervals

How much exercise?

Health guidelines suggest at least 150 minutes of moderate activity, or 75 minutes of vigorous activity, each week for adults.

How to use the target heart rate calculator

1. Enter your age. The calculator uses it to estimate your maximum heart rate.
2. Choose how to find your maximum. Use 220 minus age for the standard estimate, the Tanaka formula, or enter a maximum you have measured.
3. Add your resting heart rate (optional). Count your pulse for 60 seconds when you wake up, before you get out of bed. With this number the calculator switches to the Karvonen formula.
4. Read your zones. You will see your moderate and vigorous ranges, your maximum, your heart rate reserve and a table of all five zones.
5. Use the 10-second count. Check your pulse at your neck or wrist for 10 seconds during exercise and compare it with the pulse count shown.

Heart rate is a guide, not a rule. Heat, caffeine, stress, illness and some medicines change your heart rate. If you feel dizzy, short of breath or have chest pain, stop and get medical help.