General

Reminds me of the vending machine that used to be on the Empire State Building. It was nothing but a coin slot and a sign that said "Deposit 5¢ and listen to the wind blow". It made a lot of money!

I would think after a certain point, you would just remember the formula and be able to use it on any calculator.

The simple formula for pounds and inches:

(703 * weight in pounds) / (height in inches) ^ 2

That's 703 multiplied by your weight in pounds, divided by the square of your height in inches.

An example of a lady who weighs 250 lbs and is 5'6" would thus have a BMI of about 40.3, as shown below:

(703 * 250) / (66) ^ 2 =

(703 * 250) / (66 * 66) =

(175,750) / (4,356) =

~ 40.35

There is an even simpler formula that uses meters and kilograms, but I can't recall it off hand. However, as an American I admit I'm not used to thinking in metric.

Once you remember this, you won't need to visit a BMI web site, download yet another smart phone program, etc.


Other ratios worth remembering if you can:

1 kg = ~2.205 lbs

75 kg = 165.3 lbs
100 kg = 220.5 lbs
125 kg = 275.6 lbs

1 inch = 2.54 cm

1 foot = 30.48 cm

1 "stone" = 14 lbs (primarily the British/UK residents may use the term "stone"

18 stone = 252 lbs