BMI

[RonnieVC]

Hi,

I am a fit 67 year old weighing 66.67K.  My height is 170.64.  Using an on-line checker, my BMI should be around 22.89.  However, the Fit-bit says it is 37 - 38.  Can you explain this please?

Ronnie

[Dominique]

If you are a metric user, weigh 66.7 kg and are 171 cm tall, then your BMI is indeed 22.8, right in the middle of the normal range. Double check you are using the correct units in your profile, and have entered values that match these units. Also make sure you are looking at BMI (body mass index) and not BF (body fat), as many people tend to confuse them with one another.

[RonnieVC]

OMG, yes I’m looking at body fat. Thanks for your reply.
However, why is my body fat 37/38? That looks very high?

Sent from my iPhone

[Dominique]

If you see body fat % in your Fitbit account, it usually means you are using a smartscale (like the Fitbit Aria/Aria2 or another similar compatible scale) that syncs to your account. If so, the BF% value comes from the scale. The method used by such scales to estimate BF% (BIA) has known limitations. It can work well for some people and less so for others. You can use a site such as this one as a way to check whether the BF% estimates obtained from your scale are realistic or not.