Instructions to calculate your goal weight knowing your curr

TrainingWithTonya

How would I figure out what my current BF is?

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Ideally, you would have it tested by a professional in a lab setting to get the most accurate results, but that isn't feasible for most people. There are online calculators that you can use but who knows how accurate their formula is. Whatever method you choose, you have to stick with the same method to be able to compare the results over time. Here is a blog post I did a while back explaining the different ways of determining body fat and including a formula from the American Council on Exercise that you can use to figure it at home with your measurements. http://www.myfitnesspal.com/blog/TrainingWithTonya/view/determining-body-fat-104431

MusicKeepsMeSane

I'm 5'5" and had the idea goal weight of 130 lbs in mind. But according to this it says it should be 144 lbs. That just isn't a low enough number for me to achieve how thin I want to look.

_Sally_

To the OP - It really does depend on body type and other factors. I think goal body fat percentage goal is probably better than a total weight number goal.

I'm just under 5'5" (5' 4.5"), and when I was your weight I had much higher bf% (probably 33 - 34%) and my size was larger than a 10 (I think about a 12 - 14). So, while your goal weight is in the 140's my goal weight is in the 120's, likely due to frame, etc.

There is also a free calculator you can use to determine goal weight based on current weight, current bf% and desired bf%:

http://www.fat2fitradio.com/tools/ibw/

If I can get to my goal bf% (20 - 21%) without getting that low in weight, I will also modify my weight target.

I was also at my goal weight (125 - 128 lbs) for many years in my adult life (as recently as 6 years ago), so I also know it is a reasonable target weight.

_Sally_

I really have a hard time believing that a 5'5" person should be 134 pounds. That sounds almost stick-like.
My Vitality program has me at 146 lbs on my 5'4" frame to be "normal" in my BMI - and I saw his calculation sheet.
146 would have me in a size 10.
So 134 on a 5"5" person is almost anorexic. That would rougly be a size 6-8. That's just me thinking.....

ALMOST ANOREXIC??? Please tell me that was a sick joke.

I am 5'5" tall. Look at my profile picture. My wedding dress was a size 8. I weighed 138 pounds. Look at my diary. I eat 1550 or so calories per day. Do I look "anorexic" to you??? I had about 27% body fat, too. Sheesh...

Just want to remind everyone to please be respectful and not insult other posters (or respond to insults). Everyone has their own goals. There is nothing wrong with having a Size 10 goal and there is nothing wrong with having a Size 6 goal.

Please don't make me put my moderator hat on :flowerforyou:

kikkipoo

The corrected formula in the OP is the formula we use in my exercise physiology lab to determine ideal body weight. The confusion for some comes in thinking that it is all fat lost when we lose weight. This formula is only correct if you maintain your current lean body mass while losing. Most people don't maintain their lean body mass while losing weight, so I would classify it as a "goal ideal weight" instead of an absolute ideal body weight because it can and will change depending on if you add or lose muscle.

Thanks for confirming that this is accurate to the textbooks as well. There is some validation in that. I see what you're saying though about the lean body mass. When I took my measurement, I certainly did not have the muscle tone that I would like to have. My intent is to gain a significant amount of muscle during this journey, so I will continue to recalculate as I go because maintaining my current lean body mass isn't part of the equation.

kikkipoo

I'm 5'5" and had the idea goal weight of 130 lbs in mind. But according to this it says it should be 144 lbs. That just isn't a low enough number for me to achieve how thin I want to look.

It may just be that the current body fat % you used to calculate your number isn't very accurate. And it may be that you have a lot of muscle on your body so your base number is higher than most. Muscle you have counts in your base.

TrainingWithTonya

Okay, I'm going to try and clarify this formula a little better. The actual formula is:

Current Lean Body Mass / (1 - Goal Body Fat % in decimal form) to get your ideal body weight at your current Lean Body Mass.

Lean body mass will change as you lose weight. If you gain muscle while losing fat, your lean body mass will go up, meaning your ideal body weight goal will go up, too. If you lose muscle while losing fat, your lean body mass will go down, meaning your ideal body weight goal will go down, too. When you follow the formula it is designed as if your lean body mass doesn't change, so as you lose body fat and reassess your weight and body composition, you have to change the lean body mass number for the formula.

Here's an example:

200 pound person who is 15% body fat and wants to be 10% body fat.

200 x 0.15 = 30 pounds of fat
200 - 30 = 170 pounds of lean body mass (If said person's goal weight is below this number, then they have to lose muscle in order to get there, which isn't the healthiest way to lose weight.)

170 / (1 - 0.1) = 170 / 0.9 = 188.9 pounds for the Ideal body weight goal while maintaining 170 pounds of lean body mass.

If the same person goes on a crash diet instead of focusing on an exercise plan designed to focus on fat loss and loses down to 180 pounds but has their body fat tested and finds that it has gone up to 20% then their math would then look like this:

180 x 0.2 = 36 pounds of fat (Yes, that's up 6 pounds of fat!)
180 - 36 = 144 pounds of lean body mass (And that is a loss of 26 pounds of lean body mass!)

144 / (1 - 0.1) = 144 / 0.9 = 160 pounds for the ideal body weight goal while maintaining 144 pounds of lean body mass.

As you can see, they will have drastically different total body weight goals depending on their current lean body mass. Lean body mass is muscle, bones, organs, water and glycogen. Typically what is lost is either muscle or water and glycogen or a combination of both. But those are also what is gained when you increase lean body mass and increasing lean body mass is a great goal to have as it is beneficial for protecting the body from injury, adding fuel for intense workouts, and takes up less space then body fat in your clothes. And lets face it, the real reason we're all here is because we want to be a certain size or look good in our clothes!

And FYI: That 200 pound person above with 15% body fat is me at 5'6" tall and in a size 8. Weight has nothing to do with size. The ratio of body fat to lean body mass is what determines your clothing size.

servilia

And FYI: That 200 pound person above with 15% body fat is me at 5'6" tall and in a size 8. Weight has nothing to do with size. The ratio of body fat to lean body mass is what determines your clothing size.

This is not really true. In any case, thanks for the rest of your post it was informative.

TrainingWithTonya

And FYI: That 200 pound person above with 15% body fat is me at 5'6" tall and in a size 8. Weight has nothing to do with size. The ratio of body fat to lean body mass is what determines your clothing size.

This is not really true. In any case, thanks for the rest of your post it was informative.

I'm sorry you don't believe me, but yes, it is true. My classmates and professor in my exercise physiology practicum class were shocked, too, when they saw the weight on the scale when we were learning to use the BodPod and I did the body fat test. It's from lots of heavy weight training and the glycogen loading necessary to provide the fuel for all those 300 pound squats. I'm in a bulking phase right now which is why my ticker says I'm at goal, but when I start cutting again for body building competition, I'll change my ticker to show a goal weight of about 185-190 but actually the goal will be 8-10% body fat so that the muscles really show.

abyssfully

interesting!!

servilia

And FYI: That 200 pound person above with 15% body fat is me at 5'6" tall and in a size 8. Weight has nothing to do with size. The ratio of body fat to lean body mass is what determines your clothing size.

This is not really true. In any case, thanks for the rest of your post it was informative.

I'm sorry you don't believe me, but yes, it is true. My classmates and professor in my exercise physiology practicum class were shocked, too, when they saw the weight on the scale when we were learning to use the BodPod and I did the body fat test. It's from lots of heavy weight training and the glycogen loading necessary to provide the fuel for all those 300 pound squats. I'm in a bulking phase right now which is why my ticker says I'm at goal, but when I start cutting again for body building competition, I'll change my ticker to show a goal weight of about 185-190 but actually the goal will be 8-10% body fat so that the muscles really show.

I believe your stats, don't msunderstand me But it's not true that size has nothing to do with weight. You can not fit an infinite mass of muscle/glycogen into a finite space. A person with your stats (200lbs, 15%BF) is still going to be bigger in volume and measurements than a person with my stats (137lbs, 22%BF) even though my BF% is larger than yours. Congrats on your fitness and progress