1Introduction & Practical Use
"Ideal weight" has been studied and modeled by physicians and researchers for well over a century, producing several distinct formulas that each take a slightly different statistical approach to estimating a healthy target weight based primarily on height and gender. The CalcEqual Ideal Weight Calculator computes results from four of the most widely cited formulas — Devine, Robinson, Miller, and Hamwi — alongside the broader healthy BMI-based weight range, giving you a comparative view rather than relying on any single formula's specific output.
These formulas were originally developed for distinct clinical purposes — several were created specifically to estimate appropriate medication dosing based on body weight, not as general wellness targets — which is an important context often lost when the formulas are casually applied as fitness or aesthetic goals. Clinicians sometimes use these formulas today for calculating drug dosages, nutritional requirements, or anesthesia planning, contexts where a population-average weight estimate based on height remains clinically useful.
For general personal health goals, most contemporary dietitians and physicians now recommend treating the broader healthy BMI weight range as a more practically useful target than fixating on any single formula's specific number, since individual factors like frame size, muscle mass, and overall body composition meaningfully affect what a genuinely healthy weight looks like for any particular person at a given height.
Comparing all four formulas side by side, as this calculator does, also helps illustrate that "ideal weight" was never meant to be a single precise number — the formulas typically produce results within a reasonably similar range of each other, reinforcing that any one of them should be treated as an approximate reference point rather than a strict target.
These formulas remain in active clinical use today specifically within pharmacy and anesthesiology practice, where calculating an appropriate ideal body weight remains relevant for determining safe medication dosing in certain drug classes, even as general wellness guidance has shifted toward broader BMI-based ranges.
2The Core Mathematical Formula
Devine (Men): IBW = 50 + 2.3 × (height in inches − 60)
Devine (Women): IBW = 45.5 + 2.3 × (height in inches − 60)
Robinson, Miller, Hamwi: Similar structure with different base constants and slopes
IBWIdeal Body Weight in kilograms (converted to pounds for display)
heightHeight in inches, with the formula referencing height above the 5-foot (60-inch) baseline
2.3 (or similar)The per-inch weight increment above 5 feet, varying slightly by formula and gender
3Comprehensive Unit Definitions
- Devine Formula: Originally published in 1974 specifically for calculating drug dosages, now the most widely used ideal weight formula in clinical medicine.
- Robinson Formula: A 1983 modification of the Devine formula using a slightly adjusted slope, intended to improve accuracy.
- Miller Formula: Another 1983 alternative with different base constants, sometimes preferred in specific clinical contexts.
- Hamwi Formula: One of the earliest such formulas, originally developed in 1964, historically popular in dietetics practice before more recent alternatives gained favor.
4Historical Context & Industry Standards
The Devine formula — by far the most clinically influential of the four — was published by Dr. B.J. Devine in 1974 in a letter specifically addressing how to estimate ideal body weight for calculating drug dosages in clinical pharmacy settings, not as a general wellness benchmark. Its continued widespread use today, including in pharmacy and anesthesiology dosing calculations, reflects this specific clinical origin rather than any claim to represent an aesthetic or fitness ideal.
Modern clinical and public health guidance, including from the CDC and WHO, has increasingly shifted toward recommending BMI ranges (and, where relevant, waist circumference and body composition measures) over any single ideal-weight formula for general health assessment, reserving the height-based formulas primarily for the specific clinical dosing calculations they were originally designed for.
5Step-by-Step Practical Examples
📘 Example 1 — Male, 5'10" Height
Height 70 inches (10 inches above the 60-inch baseline)
Devine: 50 + 2.3(10) = 50 + 23 = 73 kg ≈ 161 lbs
Averaging across all four formulas typically yields a similar result in the 160-167 lb range for this height
📘 Example 2 — Comparing to the Healthy BMI Range
Same 70-inch height — healthy BMI range of 18.5-24.9 translates to a weight range of roughly 129-174 lbs
The single-point formula estimates (around 161-167 lbs) fall comfortably within this broader BMI-based range, illustrating how the formulas represent one reasonable point within a wider healthy band rather than the only "correct" answer
6Reference Conversion Table
Approximate Devine formula ideal weight by height (male):
| Height | Devine Ideal Weight |
|---|
| 5'6" (66 in) | ≈143 lbs |
| 5'8" (68 in) | ≈153 lbs |
| 5'10" (70 in) | ≈161 lbs |
| 6'0" (72 in) | ≈171 lbs |
| 6'2" (74 in) | ≈181 lbs |
7Frequently Asked Questions
Which ideal weight formula is most accurate?▾
No formula is universally "most accurate" since each was derived from different populations and for somewhat different original purposes. The healthy BMI weight range is often considered a more practically useful general guide than any single formula.
Why were these formulas originally created?▾
Several, including the widely used Devine formula, were originally developed for calculating medication dosages in clinical practice, not as general fitness or aesthetic targets — an important historical context for interpreting their results today.
Should I try to hit this exact weight?▾
These formulas provide a population-average reference point based purely on height and gender. Individual factors like frame size, muscle mass, and body composition mean your personal healthy weight may reasonably differ from any single formula's output.
Do these formulas account for body frame size?▾
No — none of the four formulas in this calculator account for frame size, muscle mass, or body composition. Some older clinical practices applied frame-size adjustments manually, but this is not built into the standard formulas themselves.
8Academic & Engineering References
- [1]Devine BJ. "Gentamicin therapy." Drug Intelligence and Clinical Pharmacy, 1974 — origin of the Devine formula.
- [2]Robinson JD, et al. "Determination of ideal body weight for drug dosage calculations." American Journal of Hospital Pharmacy, 1983.
- [3]Hamwi GJ. "Therapy: changing dietary concepts." Diabetes Mellitus: Diagnosis and Treatment, American Diabetes Association, 1964.
- [4]Centers for Disease Control and Prevention — Adult BMI healthy weight range guidance, cdc.gov