How to use the heart rate zone calculator
- Choose how to get your maximum heart rate: the 220 minus age rule, the Tanaka formula or a maximum you measured yourself.
- Enter your age, or your measured maximum.
- Choose the zone method: percent of maximum, or the Karvonen method that also uses your resting heart rate.
- For Karvonen, enter your resting heart rate, then read the five zones in beats per minute.
Formula
Maximum heart rate = 220 - age, or 208 - 0.7 x age (Tanaka), or a measured value
Percent of maximum: zone rate = maximum x percent
Karvonen: zone rate = resting + (maximum - resting) x percent
Heart rate reserve = maximum - resting
The five zones use steps of 10 percent from 50 to 100 percent. Other sources use different boundaries, so treat them as a convention.
Worked example
For age 40 the 220 minus age rule gives a maximum of 180 bpm. By percent of maximum, zone 3 (70 to 80 percent) is 126 to 144 bpm. The Tanaka formula, 208 - 0.7 x 40, also gives 180 at that age, and for age 50 it gives 173.
With the Karvonen method and a resting rate of 60 bpm, the heart rate reserve is 120 bpm, and zone 3 becomes 60 + 120 x 0.70 = 144 to 60 + 120 x 0.80 = 156 bpm. The same percentages give higher heart rates because the resting rate is added in.
How good are the formulas
Formulas based on age are estimates built from group averages. An individual's true maximum can differ from the estimate by 10 beats or more, so the zones are a starting point. A measured maximum from a supervised test, or recent hard efforts tracked with a heart rate monitor, is more reliable. Never push through chest pain, dizziness or unusual breathlessness.
Percent of maximum and Karvonen
Percent of maximum is the simplest method and needs only the maximum. The Karvonen method uses the reserve between resting and maximum heart rate, so fitter people with lower resting rates get zones that are scaled to their own range. Neither is better in every case, and your coach or doctor may use another method.
Using the zones
Lower zones suit easy long sessions and recovery, middle zones suit steady endurance work, and upper zones suit short hard efforts. This page is a general fitness aid and not medical advice. Check with a doctor before starting hard exercise, especially with a heart condition or medication that affects heart rate. See your fitness level in the VO2 max calculator, pacing in the pace calculator and energy needs in the TDEE calculator.
Assumptions and limits
- Maximum heart rate is an estimate from age or a value you enter.
- The five zone boundaries (50, 60, 70, 80, 90 and 100 percent) are one convention, not a standard.
- Medications, illness, heat, caffeine and altitude change heart rate.
- Results are rounded to the nearest beat. This is not medical advice.
Frequently asked questions
How do I calculate my maximum heart rate?
One estimate is 220 minus your age. The Tanaka formula, 208 minus 0.7 times age, is another. Both are only estimates, and a measured maximum is better than either.
What is the Karvonen formula?
Target heart rate equals resting heart rate plus a percent of your heart rate reserve, where the reserve is maximum minus resting heart rate.
Which heart rate zone is best for fat loss?
No single zone is best. Total energy use and consistency matter most, and a mix of easy and hard training works for many people.
How do I measure my resting heart rate?
Count your pulse for a minute after waking, before you get up, and average a few days.