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Ideal body weight calculator

Estimate ideal body weight from height and gender using four medical formulas, plus a healthy BMI range.

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Ideal body weight calculator
Paste a height and gender and this tool estimates ideal body weight using four formulas long used in clinical and fitness settings: Devine, Robinson, Miller and Hamwi. Each predicts a healthy weight from height alone, usually within a few kilograms of one another. The tool also reports their average and, separately, the healthy weight range implied by a BMI of 18.5 to 24.9 for the same height — two different answers to "what should I weigh" worth seeing side by side.
Enter one line per person as gender;height, optionally followed by a current weight to see how far it sits from the adjusted average — for example "m;180;82" or "f;165". Switch units between metric (kg, cm) and imperial (lb, feet-and-inches like 5'10) with Units. Body frame nudges the average up or down 10% for a small or large frame, since the formulas assume medium by default. Target BMI computes a weight for any BMI you pick, not just the midpoint of the healthy range, and Decimal places sets how many digits each result shows.
Choose Table for every formula in its own column, or Text for a line-by-line breakdown — both use the same numbers. Paste several lines to compare multiple people at once, calculated independently; blank lines are ignored and Windows and Unix line endings are treated the same. These formulas were built for adult heights and don't factor in age or muscle mass, so treat the result as a starting reference, not a target to hit exactly.
Everything runs locally in your browser — nothing you enter is ever uploaded. Copy the result, download it as a .txt file, or send the output back into the input to rerun it with different options.
FAQ
Why do the four formulas give slightly different numbers?
Each formula was derived from a different population and study, so they weight height a bit differently. The average smooths that out into one representative figure.
Why is age not part of the calculation?
The Devine, Robinson, Miller and Hamwi formulas are defined purely from height and gender — none of them factor in age, so this tool doesn't ask for it either.
How does the body frame adjustment work?
It scales the average of the four formulas by ±10% for a small or large frame; a medium frame (or no adjustment) leaves it unchanged. It is a rough heuristic, not a measured calculation.
What's the difference between the average and the healthy BMI range?
The average is one predicted number from four height-based formulas. The healthy range is every weight that keeps your BMI between 18.5 and 24.9 for that height — a band, not a single figure. They usually overlap but answer slightly different questions.
Is my height, weight or gender uploaded anywhere?
No. The calculation runs entirely in your browser — nothing you enter is sent to a server.