What is the ideal weight for my height?

There is no single number — the medical formulas give a range. For example, at 5′9″ (175 cm) the four standard formulas put an adult man around 66–73 kg (146–161 lb) and a woman around 61–68 kg (134–150 lb). A healthy BMI range for that height is wider still: roughly 57–76 kg.

Which ideal weight formula is most accurate?

Devine is the most widely used clinically (it was built for drug dosing), but none of them is "most accurate" for health. They are height-only estimates that ignore muscle, frame and age — treat the spread across formulas as your range, not any single result as a target.

Is BMI better than ideal weight formulas?

BMI gives a range rather than one number, which is more honest. But both share the same blind spot: they cannot tell muscle from fat. A muscular person can be "overweight" by BMI while being very healthy.

Does ideal weight change with age?

The formulas do not adjust for age, but body composition changes as you get older — some research suggests slightly higher BMI ranges are associated with better outcomes over 65. Trends in your own weight matter more than a fixed target.

What Is My Ideal Weight for My Height? The Four Formulas Doctors Use (2026)

Type "ideal weight" into a search engine and you will find dozens of answers, because there are four competing medical formulas — Devine, Robinson, Miller and Hamwi — and they disagree with each other by several kilograms. That disagreement is the honest answer: your "ideal" weight is a range, not a number. This guide explains what each formula actually says, shows the ranges by height, and covers when the number genuinely does not matter. To get all four results for your own height instantly, use the ideal weight calculator.

The four formulas, explained

All four use the same structure: a base weight for 5 feet of height, plus an increment for every inch above it, with different values for men and women.

Formula	Men	Women	Origin
Devine (1974)	50 kg + 2.3 kg/inch over 5 ft	45.5 kg + 2.3 kg/inch	Built for calculating drug doses; now the clinical default
Robinson (1983)	52 kg + 1.9 kg/inch	49 kg + 1.7 kg/inch	Refinement of Devine from insurance data
Miller (1983)	56.2 kg + 1.41 kg/inch	53.1 kg + 1.36 kg/inch	Another refinement; kindest to shorter people
Hamwi (1964)	48 kg + 2.7 kg/inch	45.5 kg + 2.2 kg/inch	The original quick rule for clinicians

Why the formulas disagree

None of these came from studying what weight makes people healthiest. Devine's formula was invented so hospital pharmacists could estimate lean body weight for drug dosing; Hamwi's was a bedside shortcut from the 1960s; Robinson and Miller re-fitted the numbers against actuarial tables. Because each was built for a different purpose from different data, they diverge — most at very short and very tall heights. The spread between them is typically 3–7 kg, which is exactly why a single "ideal weight" figure is false precision.

Ideal weight by height: a quick table

The span of all four formulas, rounded — treat these as midpoints of a healthy range, not targets:

Height	Men (kg / lb)	Women (kg / lb)
5′2″ (157 cm)	51–59 / 112–130	49–56 / 108–123
5′5″ (165 cm)	57–63 / 126–139	54–60 / 119–132
5′8″ (173 cm)	64–68 / 141–150	59–64 / 130–141
5′11″ (180 cm)	70–73 / 154–161	64–69 / 141–152
6′2″ (188 cm)	77–81 / 170–179	69–75 / 152–165

For your exact height — in cm or feet-and-inches — the calculator shows each formula's result side by side in both kg and lb.

The BMI healthy range: a better frame

A more useful way to think about weight is the BMI healthy range: the weights that put you between BMI 18.5 and 24.9. At 5′9″ that is roughly 57 to 76 kg — a 19 kg window, all of it considered healthy. Notice how much wider that is than any formula's single answer. If your weight sits inside the BMI range, chasing a formula's precise number has no health payoff. Check where you fall with the BMI calculator.

When the number should not worry you

You lift weights or play sport. Muscle is denser than fat; every height-only formula reads muscular people as "over" their ideal. Waist measurement and body-fat percentage are better signals.
You have a large or small frame. Wrist and shoulder structure shift healthy weight by several kilograms in either direction.
You are over 65. Some research links slightly higher BMI with better outcomes in older adults; unintentional weight loss is often the bigger warning sign.
The trend is good. Direction beats position: moving from BMI 31 to 28 is a major health win even though 28 is still "overweight" on paper.

Use the formulas the way clinicians do — as a rough reference point — and judge progress by how the range, your waistline and your energy move together, not by a single number invented for drug dosing half a century ago. For anything beyond general reference, a doctor or dietitian who can see your full picture beats every formula.