Body composition measurement is inaccurate

If your body composition measurements don't seem accurate, please check the following:

1. Following measurement guidelines
   Please see our dedicated article on how to properly take a segmental body composition measurement on Body Scan, which includes being barefoot and positioning your feet correctly to ensure the measurement goes through.
2. Using the handle
   The handle must be used to achieve a successful body composition measurement! 
   - When grabbing the handle, ensure your hand and thumbs are in full contact with the electrodes on it.
   - Do not bend your elbows too much so that your bicep touches your forearm.
3. Avoid skin-to-skin contact
   - Make sure your arms and hands are not touching one another or any other part of your body.
   - Make sure your underarms are not touching your torso and your legs are not touching one another.
   - Wear long-sleeved, light clothing to prevent skin-to-skin contact.
   - See our dedicated article for more guidelines.
4. Consistency with measurements
   - Always perform a body composition measurement in the same conditions. This is because body composition results will vary during the day, due to factors such as the amount of water present in the body at any given time. 
   - Weigh yourself at the same time of day, ideally within 30 minutes of waking up.
5. Personal data
   - Make sure your profile information such as height, gender, and age are entered correctly within the Withings App. 
   - To check this, select Profile within the app and then select your name under your profile picture at the top of the screen.
   - Body composition is only available for people 18 years or older. Children and teenagers younger than 18 won't be able to access this feature.
6. User selection
   Make sure to choose the correct user when stepping on the scale.
7. Athlete mode 
   Make sure you selected the correct body type by activating or de-activating the Athlete mode in your profile in the Withings App.
8. Hydration level
   As body composition measurements are affected by hydration, avoid eating or drinking up to 2 hours before taking a measurement.
9. Cleanliness of the scale
   Click here for cleaning instructions. A dirty scale surface can lead to inaccurate or failed body composition measurements.
10. Electromagnetic interference 
    Electromagnetic devices in close proximity — such as underfloor heating systems or other electronic appliances — may affect the accuracy of your scale’s measurements. 
    For best results, place the scale on a hard and flat surface, away from potential sources of electromagnetic interference.

Important Notes:

• Your body composition values will fluctuate depending on your weight measurement values. This is because the fat mass calculation is based on total weight.
• Other external factors, such as posture or contraction of muscles, can also influence the measurements and lead to up to 2% of variations in the metrics readings. Your monthly trend will accurately reflect the evolution of your body composition.
• Fat mass + Bone mass + Muscle mass = 100% of the body composition. As there is water in muscle and fat, the water mass cannot be added to the other metrics when calculating the body composition.

Comparing other body composition scales to Body Scan

It is important to note that Body Scan might provide different body composition results than other scales for two main reasons:

• Body Scan performs a segmental body composition measurement with a handle (i.e. with 8 electrodes: 4 on the main body and 4 on the handle). As a result, the current used for the measurement is flowing from hands to feet through the body. This measurement is more accurate than a measurement on a scale without handle where the current is only flowing through the lower body (from one leg to the other). Body Scan measures an impedance that is truly representative of the body impedance value.
• Body Scan uses 3 frequencies to provide very accurate results. One of the frequencies is a high frequency (250kHz) which allows the measuring of the water inside the cells (intracellular water). Scales without a handle only measure the water outside the cell (extracellular water). By measuring intracellular and extracellular water, Body Scan will give you the most accurate results.  

Comparing Body Scan's results  to a DEXA scan/exam

Please see our article which contains the results of a 2025 study comparing results between Body Scan and a DEXA scan.

Impedance and pregnancy

The Body Scan has not been tested and/or validated for usage during pregnancy. Due to its impedance technology related to the usage of limited electric currents and for precautionary purposes, we recommend that you disable impedance-based measurement capability if you are pregnant. You can do this by enabling either Weight-Only Mode or Pregnancy Mode by going to Devices > Body Scan > Modes and make sure either mode is toggled on.

If you still encounter issues, reach out to Customer Service by clicking the Contact Us button at the bottom of the page.