Body Weight

Body Weight 

The term body weight is overwhelmingly used in daily English speech as well as in the contexts of biological and medical sciences to describe the mass of an organism's body. Body weight is measured in kilograms throughout the world, although in some countries it is still measured in pounds (e.g. United States) or stones and pounds (e.g. among people in the United Kingdom) and thus may not be well acquainted with measurement in kilograms. Most hospitals, even in the United States, now use kilograms for calculations, but use kilograms and pounds together for other purposes. Body weight of a person is theoretically the weight of the person without any items on. However, for all practical purposes, body weight is taken with clothes on but often without the shoes and heavy accessories like mobile phones and wallets.
In physics, body mass (an expression of matter that does not change due to gravity) is expressed in kilograms while body weight (which is an expression of force that includes gravity) is expressed in Newtons.

Average weight around the world
Country/Region Average male weight/kg Average male weight/lb Average female weight/kg Average female weight/lb Sample population /
age range Methodology Year Source
Brazil 72.7 160.3 62.5 137.8 20–74 Measured 2008–2009 [1]
Chile 77.3 170.4 67.5 148.8 15 and over Measured 2009–2010 [2]
Germany 82.4 181.7 67.5 148.8 18 and over Measured 2005 [3]
United States 86.6 190.9 74.4 164.0 20–74 Measured 1999–2002 [4

Estimation in children
An example of a half unfolded Broselow tape.
A number of ways to estimate weight in children have been developed. They include: Broselow tape, Leffler formula, and Theron formula.[5] The Broselow tape is based on length with weight read from the appropriate color area.
The Leffler formula is used for children 0–10 years of age.[5] In those less than a year old it is

and for those 1–10 years old it is
m = 2ay + 10
where m is the number of kilograms the child weighs and am and ay respectively are the number of months or years old the child is.[5]
The Theron formula is

where m and ay are as above.