How this calculator works
The page first estimates maximum heart rate from age, or accepts your own value. It then measures or accepts a resting heart rate and calculates heart rate reserve as the difference. Zones use the Karvonen method: each band is a percentage of the reserve added back to the resting rate. The aim selects a target band of 50 to 70 percent for weight loss, 70 to 80 percent for endurance, or 80 to 90 percent for strength and speed. The five-zone table shows the full range with a purpose for each.
Formula
Maximum heart rate = the selected age formula or your own value. Resting heart rate = beats / (seconds / 60). Reserve = maximum - resting. Zone bpm = resting + reserve x percentage / 100.
Worked example
A 35-year-old using Tanaka has a maximum of 208 - 24.5 = 183.5 bpm. A resting rate of 60 gives a reserve of 123.5. The weight loss band at 50 to 70 percent runs from 121.75 to 146.45 bpm. Zone 4 at 80 to 90 percent runs from 158.8 to 171.15 bpm.
Advertisement
Frequently asked questions
What is the difference between percent of maximum and percent of reserve?
Percent of maximum ignores the resting rate and gives a higher lower bound. Percent of reserve, used here, accounts for the resting rate and is the Karvonen method. For the same number, the reserve method usually gives a lower bpm in the easy zones.
Which zone is best for weight loss?
Weight loss depends more on total energy expenditure and diet than on a single zone. The 50 to 70 percent band is comfortable enough to sustain for long sessions, which is why it is often labelled as the weight management zone.
How often do I need to update the zones?
Resting heart rate changes with training, sleep and illness. Recheck it every few weeks, and retest maximum heart rate or use a recent hard effort when you have one.
Why do different formulas give different maximums?
Each formula was fitted to a different population and age range. The spread between them is often five to ten beats per minute, which is one reason a measured value is preferable when available.