How do I calculate LBM (Lean Body Mass)?

#1

I thought it would be a good idea to set up a topic to collect calculators and sites that people have found helpful for working out their LBM. Please share.

Macro Advice wanted
(Tom Seest) #2

I took the easy way out and paid $50.00 for a DEXA at my local university.

#3

I would love to have that option. I must find out whether it is even viable anywhere near me in France.

#4

I use the Fitbit Aria scale that reports bodyfat percentage and substract the calculated fat weight from total body weight.

I’m sure there are more accurate methods such as a DEXA scan, but I can do this regularly with no additional costs after the purchase of the scale.

At some point I’ll cross-reference this scale with the caliper method, but I don’t see a DEXA in my immediate future.

(Richard Morris) #5

I paid $100 for the same thing … but my DEXA’s resolution was much lower than Toms.

So there is a Lean Body Mass calculator here Lean Body Mass Calculator

But for me it calculates the following;

The Boer Formula Result: 71.5 Kgs
The James Formula Result: 71.2 Kgs
The Hume Formula Result: 65.6 Kgs

My DEXA calculated my LBM to: 80.38 Kgs

So clearly some variation

#6

That is a great and easy tool - thanks @richard

AND a reminder, once again, that I am eating way too much protein!

#7

The Boer Formula Result: 130.4 lbs
The James Formula Result: 131.6 lbs
The Hume Formula Result: 124.2 lbs

Using my Fitbit Aria, I calculate 131.8 lbs, which is very close to the James Formula. I wish I had a DEXA scan like @richard for confirmation, but I’m not especially muscular so I doubt there would be a significant difference.

(Peter Demarest) #8

$50, wow. I was just looking in to this at the University of Houston and they charge $150.

(AnnaLeeThal) #9

The Boer Formula Result: 97.0 lbs
The James Formula Result: 99.2 lbs
The Hume Formula Result: 94.6 lbs

That surprised me! If that calculator is correct I have more than 40lbs of body fat. Makes me want to get a DEXA even more now. $150 near me.

(In a #ketomarriage with @peggaloon) #10

The Boer Formula Result: 46.3 Kgs
The James Formula Result: 45.3 Kgs
The Hume Formula Result: 44.7 Kgs

My DEXA scan said 45.4kg

(Joel Abdul) #11

I’ve been using the Skulpt. I’ve had a DEXA done before and it lined up pretty well. It took some practice to get exact and consistent readings.

Beats the scale…Hate that thing​:pensive::grin:

(Jacquie) #12

I’ve got one, too!. I was surprised it gave me pretty good readings. :slight_smile:

Glad to heat it lined up pretty well with your DEXA.

(Bacon for the Win) #13

jealous of folks who paid $50 for a DEXA scan. Mine was $175, $150 each if I bought two. I’m 63.5 inches, 150 lbs and 38%BF! Wow, what an eye opener.

#14

So a bit more than the LBM calculator would put you at?

(Bacon for the Win) #15

the last time I used a calc I came up with 105lbs lbm and DEXA says 89lbs. I believe the scan results.

#16

My Fitbit Aria is not accurate, off by 6%-8%. I can’t remember which online calculator I used, but it was off by 8%. I think getting a DEXA is totally worth it!

#17

I guess that is just a general calculation based on an average person with your stats? Goes to show how unique we all are. @richard was saying he came in more dense than his stats showed

I guess his exercise has had an impact?

(Ashley Haddock) #18

I am confused why my lean body mass changes based on my current weight? I used the calculator @richard linked with my current weight(277) and got this:

The Boer Formula Result: 132.8 lbs
The James Formula Result: 101.5 lbs
The Hume Formula Result: 136.3 lbs

But when I put in a more normal weight (150), I get this:

The Boer Formula Result: 100.8 lbs
The James Formula Result: 103.3 lbs
The Hume Formula Result: 98.8 lbs

I realize it’s just an estimate, but shouldn’t lean body mass be the same no matter how much fat you have?

(Texan ) #19

This is a really good question. If anything I would think lean body mass would increase because most people become more active with their new found energy.
I’m sorry I couldn’t answer your question. I am interested in the answer though.

(Richard Morris) #20

Body fat is supported by an extracellular matrix of a protein called collagen - as you draw down body fat (or put it on) you are continually reconfiguring that structure, not to mention the skin to cover it. So it is possible that a 277 lb person has 130 lbs of lean mass, but by the time they weigh 150 lbs they could have reduced 32 lbs of that lean mass.