The FastDay Forum

I'm not sure I've put this post in the correct area, so I'll just apologize in advance if I didn't.

I have a question about calculating my BMI. I have a scale that does this for me. but I've recently discovered that if I find an online calculator, I get a much better number.

on my bathroom scale, I'm told I have a BMI of 39

via the online calculators, it's at 32.

anyone have any ideas as to why this is, and which I should believe?? (please say the lower number... please say the lower number)

It's a very straightforward calculation, so I don't know how they could even be different. Maybe you have entered the wrong height into your bathroom scale, since only height and weight are used in the calculation?
I'd go with the online calculator, myself...

Is it possible the your scale is giving you your body fat %? I know that's what mine gives me.

Otherwise, is it possible that you've entered your height into the scale incorrectly?

I know I entered my height correctly. and it gives me quite a variety of numbers, also including body fat %. I actually had an old scale, and I thought that was the problem, so I used a gift cert to get a new and improved scale, and it gave me the same higher bmi as the old one. it's very strange.

Skinnyminnie, I noticed the same thing. I have been using the BMI calculation on the forum but recently noticed on the Australian National Heart Foundation website it gives me a lower value, currently 24! But your difference is quite incredible!

Why not enter your data here?

Can someone remind me how to work out my BMI. I think I have entered the wrong height on the forum. I think I am actually 3 cm taller than I wrote, and that means my BMI is less than I think it is. It's something squared divided by height or weight.... I just can't remember how to work it out.

[carorees]

weight (kg)/(height [m] x height [m])

i.e. take your height in metres and multiply it by itself and use that number to divide into your weight in kg

e.g. my height squared = 1.65m x 1.65m = 2.72; my weight = 72.6 kg; 72.6/2.72 = 26.67

National Heart Foundation has me where I am aiming for under 25 BMI while still saying I need to loose 3kgs. It contradicts the tracker here. That is a bit confusing.

[carorees]

Maybe some of the online calculators are using the revised BMI which accounts for height slightly better. There's a thread in the lab, I think, about it. If you are tall, the new calculation gives a lower BMI, if short a higher BMI, average folk should be about the same.

I didn't think the new BMI was widely accepted by the medics though, so it's a bit surprising. Alternatively, it might be to do with converting from imperial to metric measures.

I had a play on the Australian Heart Foundation site, and it seems to work in two pound increments. At 148 pounds, I was BMI 23, and at 146, BMI 22. They seem to round 22.9 down to 22, whereas I'd round that up!
I guess it's good enough to give people a general picture, but we want to register every decimal point decrease.
So I reckon stick with Moogie's tracker!

Yes, with my correct height, my BMI is a whole number lower! Is there a way I can correct my height on the tracker?

[carorees]

PM Moogie and she'll do it for you when she gets a moment.