Instructions
Power on the Wii console and insert the "Wii Fit" game disc into the Wii console game disc tray.
Select the "Wii Fit Channel" to access your Mii.
Select your Mii and click "Begin" to load the profile associated with that Mii.
Enter the password using the onscreen keyboard, if prompted.
Select "Body Test" from the menu.
Stand on the Wii Fit balance board and follow the on-screen instructions. The Wii will first calculate your center of balance and posture. From that your weight will be totaled. Follow the prompts to discard any extra pounds for clothing. Enter your height when prompted. The body mass index will be calculated based on the information you input.
Select "Yes" to overwrite the profile's current weight and other data at the end of the test.