T Nation

Body Fat Formula?


Looking for a mathematical formula to calculate body fat. I don't have access to any of the special gizmos or calipers. Are there any formulas meant for lifters? According to most indexes, 6' 200lbs is waaaay too high.


No there are no formulas. The only way you can tell is by physically analyzing your body. Sorry dude.


take a picture holding up a shoe, there's an easy way to calculate it from that picture.



mass x the speed of light^2 + (square root of 7 - height in inches) = bodyfat

any more questions?


Yea, whats the formula for equatting mass to energy?


Most indexes...like the BMI? 200lbs at 6 feet is by know means to high (assuming a high percentage of that is FFM). The only formula's I can think of are used in conjunction with calipers, underwater weighing etc. Do some research, I find it hard to believe you have no access to a body composition assessment method somewhere in your area.


I know you said you don't have access to calipers but they cost 5 bucks on amazon. Also... don't mean to bust your balls or anything but your bodyfat doesn't really matter. I think you have a better idea of how much you have gained or lost than calipers can tell you. And i think that there are a couple of threads that try and describe what you should look like at a certain bodyfat percentage but i can't find them at the moment. But even then it varies by person. So what is the reason you need to know bodyfat?

Edit: also if you have amazon prime i believe you can get 3 day shipping for free..


Those would be a waste of the OP's money. In the case of calipers, you get what you pay for...and as is the case with most bodyfat testing protocol calipers will be useless in the hands of someone who has no idea how to properly use them.


Right, I know they're cheap, but like Power GnP said, if you don't know how to use them, they're not going help much. I want to know BF because I'm cutting my food down this month and don't want to lose muscle mass. I've read the article that talks about different types of leanness. I'm not sure how accurate it is because no matter how fat I get, my abdominis rectus show.

I just used this:
Factor 1 (Total body weight x 1.082) + 94.42
Factor 2 Waist measurement x 4.15
Lean Body Mass Factor 1 - Factor 2
Body Fat Weight Total bodyweight - Lean Body Mass
Body Fat Percentage (Body Fat Weight x 100) / total bodyweight

That spits out a 17.2% body fat for me. That is actually about right. I need weekly measurements, so more in depth procedures are not practical. This should give me a good enough estimate along with other factors such as eye balling, soreness, and strength decreases/increases to make sure I'm not whittling away muscle. I'm eating 1.5g or more protein per pound of body weight. Low/med/high carb cycling.

Thanks for the feedback.


Truth be told, if you're 6ft and 200lbs, you're not very big at all. And then to be cutting weight?

Unless you're a fighter or something...? In which case, you still aren't big but at least it kind of makes sense.

And with all of that, why am I reading about this in the strength sports section?


I've never known of or even heard of a person who wound up finding a practical use for such measurements in terms of "being sure of not whittling away muscle," or in other words, having measurements that caused them to change the plan.

If tests won't in any case result in a changed decision, then they are not needed.

Now, if someone wanted to do a bad diet plan that predictably will eat LBM away, then yes, a tracking method such as you have in mind would provide a needed warning signal along the way.

But there is no reason to do that.

Instead, one should use the best knowledge one has available as to how to diet and train, and then even IF there more loss of LBM than expected, the best known way is still being done.

As for the possibility that you might find yourself dragging and not training as well at some point, and therefore it might be time to stop the cut -- since no bb'ing contest or anything like that is looming -- again, calculations and equations aren't needed for that.


You are never going to learn if you don't start at some point. The value of caliper readings is not that they can be plugged into some formula that will tell you your BF%(although there is no shortage of those formulas), it's monitoring the site reading over time, along with scale weight and the mirror. I see little value in the approach you suggest.