Human body weight is a person's mass or weight. Strictly speaking, body weight is the measurement of

weight In science and engineering, the weight of an object is the force acting on the object due to gravity. Some standard textbooks define weight as a Euclidean vector, vector quantity, the gravitational force acting on the object. Others define weigh ...

without items located on the person. Practically though, body weight may be measured with clothes on, but without shoes or heavy accessories such as mobile phones and wallets, and using manual or digital

weighing scales A scale or balance is a device used to measure weight or mass. These are also known as mass scales, weight scales, mass balances, and weight balances. The traditional scale consists of two plates or bowls suspended at equal distances from a ...

. Excess or reduced body weight is regarded as an indicator of determining a person's health, with body volume measurement providing an extra dimension by calculating the distribution of body weight. Average adult human weight varies by continent, from about in Asia and Africa to about in North America, with men on average weighing more than women.

Estimation in children

There are a number of methods to estimate weight in children for circumstances (such as emergencies) when actual weight cannot be measured. Most involve a

parent A parent is a caregiver of the offspring in their own species. In humans, a parent is the caretaker of a child (where "child" refers to offspring, not necessarily age). A ''biological parent'' is a person whose gamete resulted in a child, a male t ...

or health care provider guessing the child's weight through weight-estimation formulas. These formulas base their findings on the child's age and tape-based systems of weight estimation. Of the many formulas that have been used for estimating body weight, some include the

Advanced Pediatric Life Support Advanced Pediatric Life Support (APLS) is a program created by the American Academy of Pediatrics and the American College of Emergency Physicians to teach health care providers how to take care of sick children. Pediatric assessment triangle T ...

formula, the Leffler formula, and Theron formula. There are also several types of tape-based systems for estimating children's weight, with the most well-known being the

Broselow tape The Broselow Tape, also called the Broselow pediatric emergency tape, is a color-coded length-based tape measure that is used throughout the world for pediatric emergencies. The Broselow Tape relates a child's height as measured by the tape to th ...

. The Broselow tape is based on length with weight read from the appropriate color area. Newer systems, such as the PAWPER tape, make use of a simple two-step process to estimate weight: the length-based weight estimation is modified according to the child's body

habit A habit (or wont as a humorous and formal term) is a routine of behavior that is repeated regularly and tends to occur subconsciously.

us to increase the accuracy of the final weight prediction. The Leffler formula is used for children 0–10 years of age. In those less than a year old it is

m = \tfraca_m + 4

and for those 1–10 years old it is

m = 2a_y + 10

where ''m'' is the number of kilograms the child weighs and ''a_m'' and ''a_y'' respectively are the number of months or years old the child is. The Theron formula is

m = e^

where ''m'' and ''a_y'' are as above.

Fluctuation

Body weight varies throughout the day, as the amount of water in the body is not constant. It changes frequently due to activities such as drinking, urinating, or exercise. Professional sports participants may deliberately dehydrate themselves to enter a lower weight class, a practice known as

weight cutting Weight cutting is the practice of fast weight loss prior to a sporting competition. It most frequently happens in order to qualify for a lower weight class (usually in combat sports or rowing, where weight is a significant advantage) or in sports ...

Ideal body weight

Ideal body weight (IBW) was initially introduced by Ben J. Devine in 1974 to allow estimation of drug clearances in obese patients; researchers have since shown that the

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...

of certain drugs relates more to IBW than total body weight. The term was based on the use of insurance data that demonstrated the relative mortality for males and females according to different height-weight combinations. The most common estimation of IBW is by the Devine formula; other models exist and have been noted to give similar results. Other methods used in estimating the ideal body weight are

body mass index Body mass index (BMI) is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m2, resulting from mass in kilograms and he ...

and the Hamwi method. The IBW is not the perfect fat measurement, as it does not show the fat or muscle percentage in one's body. For example, athletes' results may show that they are overweight when they are actually very fit and healthy. Machines like the

dual-energy X-ray absorptiometry Dual-energy X-ray absorptiometry (DXA, or DEXA) is a means of measuring bone mineral density (BMD) using spectral imaging. Two X-ray beams, with different energy levels, are aimed at the patient's bones. When soft tissue absorption is subtracted ...

can accurately measure the percentage and weight of fat, muscle, and bone in a body.

Devine formula

The Devine formula for calculating ideal body weight in adults is as follows: * Male ideal body weight = + × (height (cm) − 152) * Female ideal body weight = + × (height (cm) − 152)

Hamwi method

The Hamwi method is used to calculate the ideal body weight of the general adult: * Male ideal body weight = + × (height (cm) − 152) * Female ideal body weight = + × (height (cm) − 152)

Usage

Sports

Participants in sports such as

boxing Boxing (also known as "Western boxing" or "pugilism") is a combat sport in which two people, usually wearing protective gloves and other protective equipment such as hand wraps and mouthguards, throw punches at each other for a predetermined ...

mixed martial arts Mixed martial arts (MMA), sometimes referred to as cage fighting, no holds barred (NHB), and ultimate fighting, and originally referred to as Vale Tudo is a full-contact combat sport based on striking, grappling and ground fighting, inc ...

wrestling Wrestling is a series of combat sports involving grappling-type techniques such as clinch fighting, throws and takedowns, joint locks, pins and other grappling holds. Wrestling techniques have been incorporated into martial arts, combat ...

rowing Rowing is the act of propelling a human-powered watercraft using the sweeping motions of oars to displace water and generate reactional propulsion. Rowing is functionally similar to paddling, but rowing requires oars to be mechanically atta ...

judo is an unarmed gendai budō, modern Japanese martial art, Olympic sport (since 1964), and the most prominent form of jacket wrestling competed internationally.『日本大百科全書』電子版【柔道】(CD-ROM version of Encyclopedia Nipponi ...

sambo , aka = Sombo (in English-speaking countries) , focus = Hybrid , country = Soviet Union , pioneers = Viktor Spiridonov, Vasili Oshchepkov, Anatoly Kharlampiev , famous_pract = List of Practitioners , oly ...

Olympic weightlifting Olympic weightlifting, or Olympic-style weightlifting (officially named Weightlifting), is a sport in which athletes compete in lifting a barbell loaded with weight plates from the ground to overhead, with each athlete trying to successfully lift ...

, and

powerlifting Powerlifting is a strength sport that consists of three attempts at maximal weight on three lifts: squat, bench press, and deadlift. As in the sport of Olympic weightlifting, it involves the athlete attempting a maximal weight single-lift effor ...

are classified according to their body weight, measured in units of mass such as pounds or kilograms. See, e.g.,

wrestling weight classes In most styles of wrestling, opponents are matched based on weight class. Olympic and international weight classes In international competition, men's freestyle wrestling, men's Greco-Roman wrestling, and female wrestling utilize following weight ...

boxing weight classes In boxing, a weight class is a measurement weight range for boxers. The lower limit of a weight class is equal to the upper weight limit of the class below it. The top class, with no upper limit, is called heavyweight in professional boxing and ...

judo at the 2004 Summer Olympics Judo at the 2004 Summer Olympics took place in the Ano Liossia Olympic Hall and featured 368 judoka competing for 14 gold medals with seven different weight categories in both the men's and women's competitions. Japan dominated the event by taki ...

, and

boxing at the 2004 Summer Olympics Boxing at the 2004 Summer Olympics took place in the Peristeri Olympic Boxing Hall. The event was only open to men and bouts were contested over four rounds of two minutes each. Five judges scored the fighters in real time and the boxer with the ...

Medicine

Ideal body weight, specifically the

Devine formula Devine is an Irish surname derived from Ní Dhaimhín / Ó Daimhín. Notable people with the surname include: * Adam DeVine (born 1983), American actor, comedian, singer, writer and producer * Alan Devine, Irish actor * Alexander Devine, Britis ...

, is used clinically for multiple reasons, most commonly in estimating renal function in drug dosing, and predicting

pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered ...

in morbidly obese patients.

Average weight around the world

By region

Data from 2005:

By country

Global statistics

Researchers at the

London School of Hygiene and Tropical Medicine The London School of Hygiene and Tropical Medicine (LSHTM) is a public research university in Bloomsbury, central London, and a member institution of the University of London that specialises in public health and tropical medicine. The inst ...

published a study of average weights of adult humans in the journal ''

BMC Public Health ''BMC Public Health'' is a peer-reviewed open-access scientific journal that covers epidemiology of disease and various aspects of public health. The journal was established in 2001 and is published by BioMed Central. Abstracting and indexing Th ...

'' and at the United Nations conference

Rio+20 Rio or Río is the Portuguese, Spanish, Italian, and Maltese word for "river". When spoken on its own, the word often means Rio de Janeiro, a major city in Brazil. Rio or Río may also refer to: Geography Brazil * Rio de Janeiro * Rio do Sul, a ...

.Data extracted from

References

External links

*
Online calculator for Hamwi method
{{Use dmy dates, date=April 2017 Auxology Anthropometry Mathematics in medicine