Goal Weight Calculation

I discovered that I did the calculations wrong for my target weight. Lyle McDonald has a formula on his Body Composition site:

Goal Weight = Current Lean Body Mass / (1-Goal Body Fat percentage as a decimal)

My LBM is 144.4. My Goal Body Fat percentage is 15%. So the correct goal weight is:

144.4/(1-.15) = 170 lbs

Checking it backwards, if my fat percentage is 15% then my LBM is 85%:

170 x 0.85 = 144.5 – so that’s the correct formula.

I was calculating it as LBM x (1 + Body Fat percentage as a decimal) which was a number of 166 lbs. I know it’s not a huge difference but at 190.8 lbs getting to 170 seems slightly more doable than 166 lbs.

I really like Lyle’s site. Lot of good information. And better math than my own math.

NIH Calculator for body weight


Author: Doug

I'm an Engineer who is also a science geek. I was pre-diabetic in 1996 and became a diabetic in 2003. I decided to figure out how to hack my diabetes and in 2016 found the ketogetic diet which reversed my diabetes.

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