Ideal Weight Calculator

"Ideal" weight. A phrase invented by a chart that has never met you.

Use this free ideal weight calculator to find your ideal body weight in kilograms from height using the Devine formula — the equation clinicians have used since 1974, mostly for drug dosing rather than for judging anybody's appearance.

The honest framing: this is a reference point, not a goal. It knows your height and nothing else — not your frame, muscle mass, age, or how you feel. A powerlifter and a marathoner of the same height get the same "ideal" number, and both of them should ignore it.

What This Ideal Weight Calculator Does

Calculates ideal body weight (kg) from height in inches
Uses the Devine formula with a selectable base constant (50 kg male / 45.5 kg female)
Gives a clinical reference for medication dosing and general orientation
Complements BMI and body fat, both of which say more than a single "ideal" figure

How to Use the Ideal Weight Calculator

Inputs:

Height — in inches (cm ÷ 2.54; 5'7" = 67 in)
Base — the Devine constant: 50 for men, 45.5 for women

Steps:

Enter your height in inches
Set the base to 50 or 45.5
Click Calculate for ideal weight in kilograms
Multiply by 2.205 for pounds, then treat the result as the middle of a range roughly ±10%

How the Calculation Works

Men: IBW (kg) = 50 + 2.3 × (Height in inches − 60) Women: IBW (kg) = 45.5 + 2.3 × (Height in inches − 60)

The formula is anchored at 5 feet (60 in) and adds 2.3 kg per additional inch
Devine was designed for drug dosing, not aesthetics or health targets — that is its actual job in hospitals today
Alternatives: Robinson (52 / 49 kg base) reads slightly lower, Hamwi (48 / 45.5 with 2.7 kg per inch) reads higher. They disagree by several kilograms, which tells you how precise "ideal" really is
Below 5 feet the formula extrapolates downward and becomes unreliable

Worked Example: 5'9" (69 in), male base

Inches above 60: 69 − 60 = 9
IBW = 50 + 2.3 × 9 = 50 + 20.7 = 70.7 kg
In pounds: 70.7 × 2.205 = 156 lb
A healthy BMI range at that height spans roughly 128–172 lb. The "ideal" number is one point inside a 44-pound window — which is the whole problem with the word "ideal."

Tips (From People Who Have Made These Mistakes)

Treat the result as the center of a ±10% band, not a target weight
If you lift, expect to sit above the number with less body fat than someone at it. Muscle is heavy and does not care about 1974
Better progress markers: waist circumference, strength, resting heart rate, sleep, and how stairs feel
For a range instead of a point, use BMI — a healthy BMI of 18.5–24.9 covers the same territory more honestly

Frequently Asked Questions

What is my ideal weight for my height?

By Devine: 50 kg (men) or 45.5 kg (women) plus 2.3 kg per inch over 5 feet. At 5'6" that is 63.8 kg (141 lb) for men, 59.3 kg (131 lb) for women — the midpoint of a much wider healthy range.

How is ideal body weight calculated?

Most clinical formulas anchor at 5 feet and add a fixed amount per inch. Devine adds 2.3 kg per inch; Hamwi adds about 2.7. This calculator uses Devine with a selectable base.

Is ideal weight the same as healthy weight?

No. Healthy weight is a range (BMI 18.5–24.9 covers 30–40 lb at most heights); ideal body weight is a single formula output used mainly for medication dosing.

Why does the formula ask for a base value?

Because Devine uses different constants by sex: 50 kg for men, 45.5 kg for women. Everything after that is identical.

Does ideal weight account for muscle or frame size?

Not at all — it only knows height. Athletes routinely exceed it while being leaner than average, and frame size can shift a realistic target by 10%+ in either direction.

Mini Roast Disclaimer

We roast the number, not you. A formula from 1974 that was built to dose antibiotics has no business having opinions about your body.

Reality Check

Ideal body weight formulas were built for clinical dosing, not for setting personal goals, and they ignore muscle, bone structure, age, and sex differences beyond a single constant. Health lives in a range, and body composition and fitness markers describe it far better than one number from a height-based equation.

Ideal Weight Calculator

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