What is a healthy body fat percentage? (lean-to-fat ratio)

The ideal fat-lean ratio varies depending on several key points. First of all, you should know that it isn’t the same for men and for women. It also depends of your age. To help you assess if your body composition is good or bad, here are the commonly accepted levels that define the minimum, maximum and average body fat percentages of a healthy person. But first, let’s see how it works…

How does the Wi-Fi Body Scale measure fat mass?

To calculate the percentages of lean and fat mass, the scale uses a very low and harmless electrical current to measure the opposition your body presents to the its passage. As electricity doesn’t behave the same when it goes through fat, muscle, bone or fluids, our engineers were able to build an algorithm that extrapolates your body’s opposition to the current and provides you with a fat-lean ratio.

Why track your fat and lean masses?
Even though measuring the lean-to-fat ratio is tricky (your body composition constantly changes), and comparing ratios over time is only relevant if the weigh-ins are made in the same conditions, it is still a good indicator of how healthy your weight is. It basically tells you if you have an unhealthy level of fat. A normal body composition includes fat, but beyond a certain percentage, you start to be exposed to weight-related diseases (diabetes, coronary problems…). A low level of fat mass is also critical.

This is why your fat mass is a valuable information. If you track it through time you will also see how your efforts are paying off, and if your physical activity and diet really have an impact on your condition.

Healthy levels of fat mass for a fit person

1. Minimum
5% for men,
12% for women.

2. Maximum
25% for men,
32% for women.

3. Average
15 to 18% for men,
22 to 25% for women.

What does a healthy fat mass level look like?
As we said, calculating the lean-fat ratio isn’t the easiest body metric to measure. This is why we recommend that you weigh yourself regularly, at the same time, in the same conditions (food intake, exercise, 30 minutes after getting out of bed…). We also advise you to look at the general trend of the ratio, instead of worrying about this or that value.

This set of photos illustrates every level of fat mass, both for men and women (source).

The American Council on Exercise (ACE) has put out the chart below, linking each fat mass percentage to a certain condition (source). Note that the “Average” condition in this table is actually “overweight“.


Three special cases

1. Are you an athlete?
Athletes usually have a low fat-lean ratio because their muscle mass is bigger than for a non-athletic person (be aware that this rule also depends on what sport the athlete practices). This is why it is relevant to switch Body Composition Model if you are an athlete.

2. Expecting a baby?
Pregnant women can use the Wi-Fi Body Scale with absolutely no health risk. However, the fat mass measurement will not be accurate. As the baby grows, the future mother’s body composition changes drastically and the preset models loaded inside the Wi-Fi Body Scale will not be relevant anymore. If you want to, you may disable the fat mass measurement: go to “My account” then “My body scales”.

3. Do you have a pacemaker?
Persons with an implanted pacemaker should not use the Withings Wi-Fi Body Scale. We recommend you use the newly released Wireless Scale, which does not include an impedance system.

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Jonathan Choquel

Apple fan and skateboard enthusiast since the 80s, Jonathan became Content Manager at Withings after a career as Chief Editor of specialized newsstand magazines. Curious by nature, he has been interested by the globalization of culture and the impact of new technologies on our daily lives for 20 years.