Ideal Weight Calculator

Ideal body weight (IBW) formulas

Ideal weight is a concept that defines one’s healthy level of body weight. Whilst there are several formulas available, all of these are estimates that can be used on generic populations, based on variables such as gender, height or age.

Peterson’s formula (2016)

The latest published ideal weight formula is that of Peterson et al. whose accuracy was evaluated through theoretical and empirical means.

• Ideal Weight (kg) = 2.2 x BMItarget + 3.5 x BMItarget x (Height (m) - 1.5 m)
• Ideal Weight (lb) = (5 x BMItarget ) + (BMItarget / 5)) x (Height (in) - 60 in)

R. Miller’s formula (1983)

• Ideal Weight (men) = 56.2 kg + 1.41 kg per inch over 5 feet
• Ideal Weight (women) =53.1 kg + 1.36 kg per inch over 5 feet

J.D. Robinson’s equation (1983)

• Ideal Weight (men) = 52 kg + 1.9 kg per inch over 5 feet
• Ideal Weight (women) = 49 kg + 1.7 kg per inch over 5 feet

J. Devine’s equation (1974)

• Ideal Weight (men) = 50.0 kg + 2.3 kg per inch over 5 feet
• Ideal Weight (women) = 45.5 kg + 2.3 kg per inch over 5 feet

J. Hamwi’s formula (1964)

• Ideal Weight (men) = 48.0 kg + 2.7 kg per inch over 5 feet
• Ideal Weight (women) = 45.5 kg + 2.2 kg per inch over 5 feet

IBW estimation based on the BMI healthy range

• IBW min = 18.5 x BMI
• IBW max = 25 x BMI

Importance of ideal weight

Whilst these formulas help us understand what would be a healthy weight target, IBW determinations are often used clinically for prescribing drug dosages or for health loss plans.

It is important to remember that there is not an exact figure of what is the ideal weight of each individual and these formulas offer a ballpark figure we can use as target, however, this is not to say that small deviations (which remain under the healthy BMI range) are unacceptable.

Some people are able to maintain a consistent weight throughout adulthood whilst others may go through numerous diets and strict programs to regain a healthy weight after they’ve lost it. Pregnant women also undergo physiological weight changes during pregnancy. Additionally, body composition is also a factor that may influence the healthy weight status, with people of the same weight having possible different body fat percentages.

There are three main weight gain factors you should become aware of:

• Genetic inheritance – some people have a genetic predisposition to gain weight in comparison to others that have similar diet, physical activity level and lifestyle;
• Diet – unhealthy and unbalanced diets cause weight gain;
• Physical activity level – physical activity means calories burned, so by keeping a balanced level between daily calories intake and the calories burned during the day you can maintain a proper body weight.

References

Pai MP, Paloucek FP. The origin of the ideal body weight equations. Ann Pharmacother. 2000; 34(9):1066-9.

Walpole SC, Prieto-Merino D, Edwards P, Cleland J, Stevens G, Roberts I et al. The weight of nations: an estimation of adult human biomass. BMC Public Health (BMC Public Health. 2012; 12:439.

Peterson CM, Thomas DM, Blackburn GL, Heymsfield SB. Universal equation for estimating ideal body weight and body weight at any BMI. Am J Clin Nutr. 2016; 1 03(5):1197-203.