BMI number in Burn meter

As a new lower weight entered , why does not the burn meter BMI number get automaticaly reduced to adjust for the lower daily BMI for the lower weight?

Burn meter and BMI are two completely different things.

When your weight goes down, your Burn Meter number will adjust -- usually just by about 10 calories or so -- for every 3-8 pounds lost (I never paid attention to when my burn meter went down.  Even if you are losing weight every day your burn meter number will not change every day

Your BMI (using the Tools) will also go down, but I'm not really sure how many pounds each point on the scale is -- again, I never paid attention, I would just check it after every 10-12 pounds lost.

Original Post by coach_k:

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Your BMI (using the Tools) will also go down, but I'm not really sure how many pounds each point on the scale is
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This varies according to a person's height.  By definition, BMI is just weight divided by the square of height, where weight is measured in kilograms and height is measured in meters.  So if starting weight is W, height is H, and the number of kilograms lost is D, the change in BMI is:

W/H^2 - (W-D)/H^2

Set that equal to 1, and solve for D to get the simple:

D = H^2

So that's the answer:  for a person H meters tall, BMI drops by one every time they lose H^2 kilograms (or, same thing, BMI rises by one whenever they gain H^2 kilograms).

Of course since BMI is defined using metric units, it's a bit clumsier to figure out using pounds and inches instead of kilograms and meters.  Skipping details, it works out to that a person h inches tall sees a one-unit change in BMI when their weight changes by h^2/703 pounds.

For example, someone 5'8" tall is 5x12+8 = 68 inches tall, so their BMI changes by 1 whenever their weight changes by 68^2/703 = 6.6 (approximately) pounds.  If they were 6 feet tall instead, their weight would have to change by 72^2/703 = 7.4 pounds instead, and if they were 5 feet tall by only 60^2/703 = 5.1 pounds.

Thanks y'll for your reply, and Sorry for the mix up i meant BMR not BMI.

Is it true that RMR is more accurate calculation than BMR?

all burn numbers are estimates.