clcassani’s BodyBlog

I try to put a lot of information on my site so I can refer people to it when we talk about different exercises or topics, plus it’s a great way for me to store info and drills I like and need.

Here’s a good example, I’ve been looking for this formula for years, thank you to brandyTKO for sharing!!
If you want to get to a certain bf percentage how do you figure-out how much weight you need to lose. I did some calculations on myself - if I want to be 10% bf my weight needs to be at 180 lbs, that means I need to lose 26 lbs - I don’t know if that is going to happen.

Another good thing with this formula is that I calculated it with my current weight and found that the handheld bf machine is correct. Based on this formula if my bf is 20% my weight should be 202.5 lbs, I’m 206 so it seems to line up pretty accurately.

Try it out and let me know.

Regards,                  
                                                                          !CC L-Kewl
So a bit of explanation first on this calculation:

You need to know your lean body mass weight. Simply multiply your weight by your BF% to determine how many pounds / kilos of fat you have. Then subtract your pounds of fat from your total body weight to determine your pounds of muscle or lean body mass. For example if you weigh 130 pounds and your BF% is 30%, your results would look like this:

A. Total weight = 130 lbs
B. Body fat% = 30
C. (AxB)/100 - 39 pounds of fat
D. Pounds of lean body mass = A-C = 91 lbs.

Say you want your BF % to be 22% (see E in calc. below). To calculate what you should weigh at 22% BF, get your Lean Boady Mass % Goal (100-22=78) (see F in calc. below). Then divide your current pounds of lean body mass by 78 and multiply by 100 (D/78×100) (see G in calc. below). In the above example, 91 pounds of muscle divided by 78×100 = 117 pounds in other words you need to lose 13 pounds of fat (130 lbs - 117 pounds) (see H in calc. below) to retain your muscle and acheive 22% BF.

The formula to reach your goal weight is:

Goal Weight = Weight of Lean Body Mass / (100 - desired BF%) x 100.

Here is the table used in my materials which makes calculation easier, just fill in the blanks and use your calculator or your extremely sharp brain….I need to use a calculator, ha, ha.

A. Weight (lbs or kgs)   ______
B. % Fat ______
C. Fat (lbs or kgs) = (AxB) / 100 _______
D. Lean Body Mass (lbs or kgs) = A-C _________
E. Body Fat % Goal ______
F. Lean Body Mass % Goal = 100-E ________
G. Weight Goal = (D/F) x 100 _______
H. Weight Loss Goal of Fat = A-G ________

This entry was posted on Thursday, September 3rd, 2009 at 7:44 am and is filed under Training. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.