# Ideal Weight Calculator

> Calculate ideal body weight for your height and sex with the Devine, Robinson and Miller formulas, alongside the BMI 18.5–24.9 weight range.

Category: Health & fitness · Applies to: Worldwide · Last updated: 2026-10-29
Interactive calculator: https://calculators.geekmidst.com/calculators/ideal-weight-calculator

“Ideal” body weight formulas add a fixed amount for every inch over 5 feet. The Devine formula, published in 1974 for drug dosing, is still the one most used in clinical practice.

Also called: Ideal body weight calculator, IBW calculator.

## Inputs
- Sex (options: Female, Male; default female)
- Units (options: Metric (cm, kg), US (ft, in, lb); default metric)
- Height (unit cm; default 170)
- Height (feet) (unit ft; default 5)
- Height (inches) (unit in; default 7; optional)

## Results
- Devine (1974)
- Robinson (1983)
- Miller (1983)
- BMI 18.5–24.9 range

## Formula

```
Devine: men 50 kg + 2.3 kg per inch over 5 ft, women 45.5 kg + 2.3 kg;  Robinson: men 52 + 1.9, women 49 + 1.7;  Miller: men 56.2 + 1.41, women 53.1 + 1.36
```

Where:
- inches over 5 ft: height in inches (cm ÷ 2.54) minus 60
- results: shown in kg (metric) or lb (US)

## Worked example
1. 170 cm ÷ 2.54 = 66.93 in, which is 6.93 in over 5 ft.
2. Devine: 45.5 + 2.3 × 6.93 = 61.4 kg.
3. Robinson: 49 + 1.7 × 6.93 = 60.8 kg; Miller: 53.1 + 1.36 × 6.93 = 62.5 kg.
4. BMI range: 18.5 × 1.70² = 53.5 kg to 24.9 × 1.70² = 72.0 kg.

**Result:** For a woman 170 cm tall the formulas give 60.8–62.5 kg (Devine 61.4 kg), well inside the BMI-based healthy range of 53.5–72.0 kg.

## What the result means

These are single reference weights, not targets. The BMI range shows how wide a healthy weight can be at the same height; frame size, muscle and age all shift where you sit within it. Clinicians mainly use the Devine value to dose certain medicines and set ventilator volumes.

## Assumptions and limits
- Adults 5 ft (152.4 cm) or taller; the formulas are not defined below that height.
- Formulas as compiled by Pai and Paloucek (2000).
- The formulas were not derived from health outcomes; Devine’s was an estimate for drug dosing.
- They take no account of body composition, frame size, age or ethnicity.

## Questions

### Which formula is most accurate?

None is “accurate” in a health sense. They give similar results near average heights and diverge for very short or very tall people; the BMI range is a broader guide.

### Why is there no result under 5 feet?

All three formulas start at 5 feet. Some clinicians subtract per inch below that, but that is an extrapolation the original authors did not publish.

## Sources
- [Pai MP, Paloucek FP. The origin of the “ideal” body weight equations. Ann Pharmacother, 2000](https://www.researchgate.net/profile/Manjunath-Pai/publication/258125580_The_Origin_of_the_Ideal_Body_Weight_Equations/links/0a85e53bfe73e41443000000/The-Origin-of-the-Ideal-Body-Weight-Equations.pdf)

## Related calculators
- [Healthy Weight Calculator](https://calculators.geekmidst.com/calculators/healthy-weight-calculator)
- [BMI Calculator](https://calculators.geekmidst.com/calculators/bmi-calculator)
- [Lean Body Mass Calculator](https://calculators.geekmidst.com/calculators/lean-body-mass-calculator)
- [Body Fat Calculator](https://calculators.geekmidst.com/calculators/body-fat-calculator)

_This is a general screening estimate for adults, not medical advice or a diagnosis. Talk to a qualified health professional about your health._

Source: GM¹X CalcVerse — https://calculators.geekmidst.com/calculators/ideal-weight-calculator