Body fat % and lean body mass...need help

I would like to know this too!

bump

http://www.cordianet.com/calculator.htm

Try this calculator. Put in all your info and what you want your body fat percentage to be and it will tell you what you have to weigh to be around the number. How did you measure your body fat percentage? There are a few methods out there and a scale that measures it can be off a few percentage points.

Not really. Because as you lose fat, you will also lose some lean mass. So your ideal weight will include a lower lean mass number than what it would appear to be right now.

There are many charts that give an idea of a healthy weight, but it depends greatly on body type, age, bone mass, muscle mass, etc. Some good info on goal weight in this thread, with a chart on the 2nd page:

http://www.myfitnesspal.com/topics/show/181080-mfp-s-most-common-user-pitfall-to-avoid

I'm 278 lbs with 42% body fat. So when I do the math (278 x 0.42) I get 116 which I understand to be the pounds of fat in my body...right? If so, does that mean that I have 162 lbs of lean body mass? And does that mean I shouldn't weigh less than 170ish lbs?

You're right -- you have 116 pounds of fat and 162 pounds of lean body mass. Lean mass is muscles, organs, bones, connective tissue, etc. AKA "healthy mass". Going down to 8 pounds of fat is not a realistic goal for pretty much everybody except for the most elite athletes. Here is a body fat scale of healthy body fat ranges:



I'm not saying this is gospel, this is just one website's opinion. I think your goal should be to get into the Normal to Fit range. Now, as for what goal weight that will make you -- that's hard to say. With dramatic weight loss comes almost automatically with some mixture of lean body mass and fat -- even to those who were most diligent about retaining their muscle mass. Why don't you set your goal weight to some number which you think is reasonable now, and re-evaluate when you get closer? Remember -- weight is an arbitrary number that fluctuates wildly with hydration levels and can really play games on you. Your real goal should be to lose body fat. Take pictures, measurements, and keep measuring your body fat. Those will be the real testament to your progress!

Good luck!

My gym uses those handheld things too, and I've found its not very reliable after a workout. You've just sweat, drank water, etc. I use it as a baseline but I don't take the number as 100% accurate. I've had it tell me 27.4%, and 28.2% and 29.2% all while at the same weight and within a few weeks of each other, so it tends to fluctuate.

As you progress throughout your workouts, you will replace a lot of the fat with lean body mass. This is also why it is important to do weight training to increase your lean muscle mass. And more muscle means more calories burnt and more food you can eat! I would like to say, that is a great chart. I would like to commend you in finding out a rough estimate of your body fat. Even though the machines aren't that accurate, it is still better than not knowing. I would suggest getting some body fat calipers to continue to track your body fat/get a better reading. Body compisition is better and more important than weight. Also, get a good measuring band to get measurements. I would also like to say, that is an awesome chart.