Body fat calculator (US Navy Method)

middlehaitch

pismodiver wrote: »

The real value of a calculator like the USN one is not so much the number it gives, but to take serial measurements and use it to compare current you to past you. I like it because it's simple and repeatable.

The USN and my scale come out very similar, 19.?.

In real life I know I am closer to 22-23, carry all my fat between my ribs and pelvis, but like you say, they are a reasonable indicator.

Right now, I’ve not been lifting during covid and can visibly see the body change, flaccid, and my scale is showing 20.? Instead of my usual 19.?

It is a gauge, not a precise measurement for me.

Cheers, h.

AnnPT77

yirara wrote: »

AnnPT77 wrote: »

yirara wrote: »

AnnPT77 wrote: »

Pipsqueak1965 wrote: »

I get 19.8 body fat (athlete!) But 31% BMI - so I am not following? I would guess realistically I'm around 22-24% body fat.

@Pipsqueak1965, What do you mean by 31% BMI?

Is it the "Body Fat (BMI Method)" in the results of the first calculator? In my results, that value (34.5%, in my case) seems like it might be the body fat percent that might be statistically inferred from BMI & age.

For example, putting it another way, if I put that body fat percent into one of the BMI calculators that will use BF% (such as Sailrabbit), I get a BMR result similar to what I'd get if I just put in my age/weight/height but no BF% (if I let it assume a BF%, in effect); but if I put in a more realistic BF% estimate for me, I get a higher BMI estimate (not surprisingly). That's what makes me think it could be a statistically/demographically estimated BF%.

https://www.sailrabbit.com/bmr/ is the multi-formula site, if you want to play with it to see if something similar is true with your numbers.

ah, just played with sailrabbit again. I'm someone whose numbers don't add up: BMI of 21, body fat according to various calculators like the one above around 30-31. When I use a fat of 22% then Katch-McArdle get in the range of my TDEE for sedentary and Cunningham overestimates. Interesting. Using 30% fat I'm way below my sedentary TDEE.

Suspect BMR/TDEE can vary for reasons other than BF%. My point in the Sailrabbit reference in this thread was to support my speculation that BMR estimated without body fat percent implicitly relies on an implied body fat percent, and that implied (statistical artifact) body fat percent may be what the "Body Fat (BMI Method)" label is referring to. I admit it's speculative.

But none of that speculation relies on the idea that Sailrabbit (or any other calculator) is right on for any specific person, with any particular set of (accurate) inputs. For sure, its sedentary TDEE estimate for me is wrong by a few hundred calories at sedentary, with or without a reasonable BF% input. (It's a little closer with a BF input, that's all.) I don't know whether the discrepancy (vs. 5+ years of logging experience) is in BMR or multiplier or my logging practices, don't see how I could know unless I pay $$ for a metabolic lab test. Don't care, personally. I know how much to eat to lose/gain/maintain; that's all I care about, really.

Yeah, agree. I'll never know. This kind of testing is ridiculously expensive to not available here. I know I can eat a decent amount of food and maintain my weight even without exercise. And I'm certain I don't have <30% fat as that would be a rather odd combination.

I'm not sure I'm understanding you correctly: Are you saying there would be something odd about having a BMI of 21, but body fat less than 30%? If so . . . what about that seems odd, out of curiosity?

heybales

So the formula's for those methods give away which body parts are actually used - like on the gymtools that gets 3 measurements. (I'm just pulling from a spreadsheet)
It shows that if you happen to have a body part you know full well is very outside the average (like maybe huge calves), it could skew 1 calc but not be used in another one.

Navy Circ method:
if(gender="m",86.01*LOG(A27*2.54-A25*2.54)-70.041*LOG(height)+30.29521038,163.205*LOG(A26*2.54+A28*2.54-A25*2.54)-97.684*LOG(height)-104.9121099))

Covert method:
if(gender="m",if(age<31,A27+0.5*A28-3*A24-A23,A27+0.5*A28-2.7*A24-A23),if(age<31,A28+0.8*A29-2*A30-A23,A28+A29-2*A30-A23))

Cells referenced:
A23 - wrist (Covert men & women)
A24 - forearm (Covert men)
A25 - neck (Navy women & men)
A26 - waist (Navy women)
A27 - abdomen (Navy men & Covert men)
A28 - hips (Navy women & Covert men & women)
A29 - thigh (Covert women)
A30 - calf (Covert women)

What I've seen happen with several people in the known unaverage body part as they lose fat - 1 calc goes down faster than the other.

ETA:
At the time of 2 bodpods in the past, Navy was over, Covert was under, by 1-2% each.