How Do Our Smart Scales Measure Body Fat?

Health Articles
March 9, 2018

When a celebrity asked how our scales measure body fat we had to answer the call. In this case “the call” was actually a tweet, but still, it’s a good question that deserves a good answer. Find out what goes into the number you see on your Withings smart scale and in your app, below.

Our body composition smart scale models, Body+ and Body Cardio, use the bio-impedancemetry analysis (BIA) method. The scale sends an undetectable current from four electrodes located on the scale pan through your feet, legs, and abdomen. This signal quickly passes through the water present in the hydrated muscle tissue, but it is confronted with the resistance of adipose tissue (your fat).

Total body water can be used to estimate fat-free body mass and, by difference with body weight, your fat mass.
If you want to go deeper, one thing to note is that:

fat mass + bone mass + muscle mass = 100% of body composition

Because water is in muscle and fat, water mass cannot be added to the other metrics when calculating the body’s composition.
It should be noted that all our scales are highly accurate, automatically sync to the free Health Mate app, and can track up to 8 users with independent sync.

Since it is important to weigh yourself regularly, and morning is often the best time of the day to weigh yourself, all Withings scales can deliver a local weather report so you know how to dress when you get out of the shower. Incidentally, the weather report also updates throughout the day, so you can step on whenever if you get the urge.
All our scales also allow you to activate the Pregnancy Tracker program for healthy gain (with body composition readings deactivated), and use Baby Mode, to help you weigh the smallest members of your family just by holding them in your arms. Baby mode is also very popular with pet owners…
Note: people with a pacemaker shouldn’t use Body+, Body Cardio or any BIA scale and people with any internal medical device should consult their doctor before using one. For these users, we recommend our Body scale, which is a Withings smart scale that doesn’t compute body composition, but tracks highly-accurate weight and BMI, and offers the other features.
So—now know everything about how to calculate the fat mass and you are ready to go discover our whole range of Withings smart scales.