Ideal Weight Calculator

Step on the scale and feel good or bad about the number. It's a reflex most people have developed over years of being told their weight either is or isn't where it should be. But "ideal weight" is far less precise a concept than it sounds, and the formulas used to calculate it were developed for purposes that have almost nothing to do with how we use them today.

Healthy Weight Ranges and BMI: Related but Different

You'll sometimes see ideal weight discussed alongside BMI (Body Mass Index), which is weight in kilograms divided by height in meters squared. A BMI between 18.5 and 24.9 is generally considered healthy. Most ideal weight formulas produce results that land within or near this BMI range for average adults — which is by design, since they were calibrated against population health data.

But BMI has the same limitation: it knows your height and weight, nothing else. A BMI of 27 (slightly "overweight") in an athletic person with low body fat is a different situation than a BMI of 27 in a sedentary person with high visceral fat. The number is the same. The health implications can be quite different.

Related Calculators

• BMI Calculator
• Body Fat Calculator
• Lean Body Mass Calculator

Where These Formulas Actually Come From

The three most commonly cited ideal weight formulas — Devine, Robinson, and Miller — all originated in the medical literature, and none of them were designed to define fitness or beauty standards. They were developed to help clinicians estimate appropriate drug dosing in patients of different sizes. The goal was pharmacological, not aesthetic.

Dr. B.J. Devine published his formula in 1974 to improve medication dosing accuracy. For men, it calculates ideal body weight as 50 kg (110 lbs) plus 2.3 kg for every inch above five feet. For women, it starts at 45.5 kg (100.3 lbs) plus 2.3 kg per inch above five feet. At 5'10", the Devine formula suggests about 82.1 kg (181 lbs) for men and 77.7 kg (171 lbs) for women.

Robinson modified this in 1983, arriving at slightly different baseline numbers: 52 kg for men, 49 kg for women, plus similar per-inch adjustments. Miller's 1983 formula differs again. The practical result is that for any given height, these three formulas might produce a range of answers spanning 15–20 pounds — all of them "ideal" according to someone's research. That spread should give you pause about treating any one of them as a precise target.

What These Formulas Miss

Here's the thing: none of these formulas have any information about your body composition. A 5'10" woman who has been strength training for five years and carries significant muscle mass will look and feel very different at 171 pounds than a 5'10" woman of the same weight who is sedentary. One might be extremely lean and athletic. The other might have a body fat percentage well above healthy ranges.

Weight alone can't distinguish them. And ideal weight formulas built purely on height don't even try. This is the fundamental limitation. Two people at the same height "should" weigh the same according to the formula, but their bodies are different systems with different compositions, and the number on the scale represents all of it — fat, muscle, bone, water, organs — with no differentiation.

A Real Example: When the Formula and the Mirror Disagree

Jasmine Torres, 29, from San Diego, stands 5'5" and weighs 142 pounds. The Devine formula suggests her ideal weight is about 123.2 lbs. Robinson puts it at 127.5 lbs. By those formulas, she's 14–19 pounds "overweight." But Jasmine runs three times a week, lifts weights twice a week, and her recent physical showed excellent blood pressure, blood glucose, and cholesterol levels. Her body fat percentage, measured by DEXA, is 22.4% — athletic range for her age.

She's not overweight. She's muscular. The formula, designed for drug dosing in a general population with average muscle mass, just doesn't account for that. Understanding this context let Jasmine stop fixating on a number that didn't apply to her and focus instead on how she performed and felt.

The More Useful Number: A Weight Range

Rather than a single ideal number, most health professionals work with ranges. The Hamwi formula — another commonly used calculation — produces a baseline for men of 106 lbs for 5 feet of height plus 6 lbs per inch above that, and 100 lbs for women plus 5 lbs per inch above five feet. From this baseline, a range of ±10% is generally considered within normal limits for frame size variation.

For a 5'8" man, this produces a baseline of about 154 lbs and a healthy range of roughly 139–170 lbs. That's a 31-pound range from low to high — reflecting the real variation in bone density, frame size, and muscle mass that exists across people of the same height. If you're within this range and feel healthy, have good energy, and your medical markers are solid, you're probably not far from your personal ideal weight regardless of where within that range you fall.

What to Actually Target

Rather than chasing a specific number from a formula, most people are better served by identifying a personal goal range — a window of roughly 10–15 pounds — and focusing on the behaviors that produce health outcomes rather than the weight outcome itself.

Those behaviors: maintaining muscle mass through resistance training, eating adequate protein, getting regular cardiovascular activity, sleeping well, and managing stress. People who do these things consistently tend to find their weight settles somewhere in a healthy range without obsessive tracking or extreme restriction.

The ideal weight formulas in this calculator are useful reference points for understanding how your current weight compares to statistical expectations for your height. Use them as context, not as commands. Your actual ideal weight is the one at which you have good energy, strong performance, and healthy biomarkers — and that varies considerably from person to person.