Ideal Weight Calculator
Find your ideal body weight target using the classic Devine formula.
How to use
- Select your units and gender, then enter your height.
- Click Calculate.
- See your ideal weight and a healthy range.
For information only — not medical advice. Consult a healthcare professional for personal guidance.
What Is an Ideal Weight Calculator?
"Ideal weight" formulas estimate a healthy target weight for your height, giving dieters, athletes, and clinicians a reference point that the bathroom scale alone cannot provide. This calculator uses the Devine formula — the most widely used of the classic height-based equations — and takes your gender and height in imperial (feet and inches) or metric (centimeters). The result is best understood as the center of a healthy range, not a single magic number your body must hit.
Height-based formulas exist because weight means little without height: 75 kg is lean on a 193 cm frame and heavy on a 160 cm frame. The classic equations were derived from actuarial and clinical data in the mid-twentieth century and remain in everyday use, particularly in medicine, where the Devine formula is still used to dose certain drugs and set ventilator parameters.
How to Use the Ideal Weight Calculator
- Choose imperial or metric units.
- Select your gender — the formula's baseline differs for men and women.
- Enter your height: feet plus inches, or centimeters.
- Click Calculate to see your ideal weight estimate.
The Devine Formula
Published by Dr. B.J. Devine in 1974, the formula starts from a base weight at 5 feet tall — 50 kg for men, 45.5 kg for women — and adds 2.3 kg for every additional inch of height. A 5'10" man, for example, gets 50 + (10 × 2.3) = 73 kg. Cross-check the result against the BMI healthy range for your height (BMI 18.5–24.9): the two methods usually bracket a similar zone, and the truth for any individual — especially the muscular or the very slight — sits somewhere within or even outside both, which is why ranges beat point estimates.
Tips for Using an Ideal Weight Target
- Aim for the range, not the decimal: being within roughly 10% of the estimate is, for most purposes, being at an ideal weight.
- If you carry substantial muscle, expect your healthy weight to sit above the formula — muscle is dense, and the equation assumes an average build.
- Pair the target with a waist measurement: a waist under half your height is a simple, well-supported health marker whatever the scale says.
How accurate is the Devine formula?
It is a population average dressed as an equation — reasonable for people of average build, noticeably off for the very muscular, the very lean, and those with larger or smaller frames. It was designed for clinical convenience, not as a verdict on any individual. Use it as one reference among several, alongside BMI range, waist circumference, and how you actually feel and perform.
Why do different formulas give different ideal weights?
Devine, Robinson, Miller, and Hamwi each fitted slightly different lines to different datasets between 1974 and 1983, so their results differ by a few kilograms — Robinson tends to run lighter, Miller heavier for tall people. The disagreement between formulas is itself information: it tells you the honest precision of the concept. A band several kilograms wide is the real answer.
Should children use this calculator?
No. These formulas were built for adults whose growth is complete. Children's healthy weights are assessed with age- and sex-specific growth percentiles, because a healthy weight for a ten-year-old depends on developmental stage, not just height. For anyone under 18, a pediatrician's growth charts are the right tool.
What if my ideal weight seems impossibly low or high?
First, double-check the height entry — a one-inch error moves the result by 2.3 kg. If the number still surprises you, remember the formula knows nothing about your frame, muscle mass, or history. People who have carried more muscle or weight for years often thrive at the top of, or above, the classic range. Discuss personal targets with a clinician when health conditions are involved.