What “ideal weight” formulas actually are
The four equations on this page are mid-20th-century reference formulas based only on height and sex. Devine (1974) is still widely quoted and was originally discussed in the context of estimating drug doses, not of setting a wellness goal. Robinson (1983) and Miller (1983) are later variations. Hamwi (1964) is another height-based rule of thumb. All of them add a fixed number of kilograms for each inch above 5 feet, with different intercepts for the male and female equations.
FuelCount shows each result and the average so you can see the spread instead of pretending there is one official weight. Two formulas can differ by several pounds at the same height. That disagreement is the point: “ideal” here means “the number a particular equation prints,” not “the weight every healthy person of this height should be.”
These models ignore muscle, bone structure, age, pregnancy, and fat distribution. A strength athlete and a sedentary person of the same height can both be healthy and sit far from the average line. BMI, waist measurements, and a body-fat estimate answer other questions and also have limits. If you want a composition estimate from a tape, use the Navy body fat calculator. If you want calories rather than a target weight, start with the TDEE calculator.
The tool restricts height to a rough adult range (about 4'6" to 7'0", or 137–213 cm) because the equations were not built for children and become shaky at extreme statures. Even inside the range, treating the output as a mandated goal can be harmful, especially for anyone with a history of disordered eating. A healthier use is narrow and technical: you needed a classic reference number, and you wanted to see how the common formulas compare.
If a clinician has already given you a weight range based on your history, that clinical range outranks a 1970s equation on a website. This page will not try to override it.
Frequently asked questions
Which formula is the most accurate?
None of them is an accuracy contest in the modern sense, because they do not estimate fat or health. Devine is the most commonly copied. Showing four results is more honest than crowning a winner. If you only need a single reference figure, the average is a compromise, not a discovery.
Why do the male and female equations differ?
The original authors published separate regressions. The difference is a property of those papers, not a complete account of sex, hormones, or body composition. People whose bodies or identities are not well described by that binary choice should treat the output as even more approximate.
Can I use this to set a weight-loss goal?
It is a weak way to set a personal goal. A slower plan aimed at habits, strength, and a weight range you can live with usually beats chasing a formula. If you do set a number, talk it over with a qualified professional, especially if you have a medical condition or a difficult history with weighing yourself.
How is this different from BMI?
BMI uses height and weight to produce a ratio; these formulas try to produce a weight from height alone. Both are crude. BMI at least uses your actual weight. Neither replaces a clinical assessment.
Do the formulas work for older adults or teenagers?
They are adult height rules of thumb and are a poor fit for children and adolescents, whose healthy weight is assessed differently. Older adults may also be poorly described by a single height-based target. Do not use this page as a growth or geriatric assessment.