Ideal Weight Calculator

Ideal Weight Calculator delivers exactly what its name promises, find your ideal body weight (devine, robinson, miller, hamwi) & healthy range, fast and free. Because it belongs to ToolsMonk's medical tools collection, the whole workflow happens on a single page instead of being spread across separate apps or websites.

Common scenarios include you want a realistic weight range rather than a single number, and want to see how much the standard formulas disagree, a clinician mentioned ideal body weight in the context of drug dosing and you want to understand where the figure comes from, and you are setting a fitness goal and want it anchored to something more considered than a round number. The browser-based design means you can switch devices mid-task and pick up right where you left off, whether it's a one-time job or part of a daily workflow.

It is built for getting a real result on the first visit: no learning curve, no account, and the wider ToolsMonk toolbox close at hand.

Ideal body weight formulas are older than most people assume, and they were not designed to tell you what to weigh. Hamwi published in 1964, Devine in 1974, and Robinson and Miller both in 1983. Devine in particular was written to standardise drug dosing, and it survives in clinical practice for that reason rather than as a health target.

All four share a structure: a base weight at five feet, plus a fixed amount for every inch above that. They differ only in those two constants and in how they treat men and women. That is why they produce answers that cluster but never agree, and why presenting a single one as the ideal weight overstates what any of them can tell you.

The formulas are linear, which is fine inside the range they were fitted to and nonsense outside it. Below five feet they trend toward zero, so this calculator floors the excess term at zero and each formula returns its own base weight instead. Anyone shorter than that range, and anyone still growing, is better served by a different method entirely.

This is why the healthy BMI range is shown next to the results. A BMI of 18.5 to 24.9 at your height gives a band that is typically several kilograms wide, and a band is a more honest answer than a point estimate. Neither can see body composition: a rugby player and a sedentary person of the same height get the same ideal weight from every one of these formulas.

Use this as one input among several. Waist-to-height ratio says more about metabolic risk than total weight does, and body-fat percentage says more still. All of it is calculated in your browser with nothing uploaded and no account, and none of it is a substitute for a clinician who can see the whole picture.