The Truth About Ideal Weight Charts

Google "ideal weight for my height" and you'll get a dozen different answers. The Devine formula says one thing. The Robinson formula says another. The Hamwi formula gives yet another number. They were all developed decades ago, using different populations and different assumptions. So which one is right?

Four Formulas, Four Different Answers

The most commonly used ideal body weight formulas were developed between the 1960s and 1980s. None of them were designed with the rigor you'd expect from modern clinical research:

Devine (1974) — originally created to calculate drug dosages, not to define "ideal" weight. It was never validated against health outcomes. Yet it became the most widely used formula in clinical settings.

Robinson (1983) — a modification of Devine that tends to give slightly lower estimates for men and higher for women. Better balanced, but still based on Metropolitan Life Insurance actuarial tables from the 1950s.

Miller (1983) — tends to give the highest estimates of the four. More forgiving for larger frames.

Hamwi (1964) — the oldest of the bunch. Simple to calculate but based on very limited data. Still taught in some nutrition programs.

Our ideal weight calculator shows you all four results side by side. The spread between the highest and lowest can be 10-15 pounds for the same person. That should tell you something about how precisely these formulas can pin down your "ideal" weight.

Why These Formulas Fall Short

Every one of these formulas uses only height as an input. That's it. No age, no body frame, no muscle mass, no ethnic background. A 5'10" 25-year-old swimmer and a 5'10" 65-year-old with osteoporosis get the same "ideal" weight. That should raise an eyebrow.

They also carry the biases of their source data. Metropolitan Life tables were based on predominantly white, middle-class Americans who bought life insurance in the mid-20th century. Applying those numbers globally is a stretch.

What "Ideal" Actually Means

In clinical practice, "ideal body weight" is mostly used for drug dosing and ventilator settings — situations where a standardized estimate of lean body mass is needed quickly. It was never meant to be the weight you should aspire to for optimal health.

For health, what matters more is your body composition. You can be at your "ideal" weight and still carry too much visceral fat. You can be 20 pounds above it and be metabolically healthy with good muscle mass. The number on the chart is a reference point, not a verdict.

A Better Approach to Weight Goals

Instead of chasing a single number from a 50-year-old formula, use multiple data points:

Start with your BMI for a rough screening. Then check your body fat percentage for a composition-level view. Factor in waist circumference — it's one of the best predictors of metabolic health risk. Consider your energy levels, sleep quality, and how you feel day to day.

If you want a weight target for practical planning (figuring out your calorie needs or macro split), use the ideal weight range as a rough guide. Just don't treat any single formula as gospel.

The Number That Matters Most

Here's what I'd tell anyone obsessing over their "ideal" weight: the best weight for you is the weight at which your blood markers are healthy, your energy is good, you can do the activities you enjoy, and you can maintain it without misery. No formula can calculate that. Only your body and your doctor can tell you.