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Ideal Weight Calculator

A free online ideal weight calculator that estimates your ideal body weight using four established clinical formulas — Devine, Robinson, Miller, and Hamwi — side by side, adjusted for small, medium, or large body frame size. Also shows the BMI-healthy weight range for your height.

Why four different formulas?

Devine, Robinson, Miller, and Hamwi are all long-standing formulas originally developed for clinical contexts like medication dosing, and each produces a slightly different estimate for the same height. None is definitively "more accurate" than the others — showing all four together, plus their average, gives a more honest picture than presenting a single number as if it were exact.

The body frame adjustment

All four formulas were originally built around an average-frame assumption. This calculator applies a rough ±10% adjustment for a small or large body frame, since someone with a naturally larger or smaller bone and frame structure at the same height reasonably has a different healthy weight range.

How this relates to BMI

"Ideal weight" formulas and BMI-based healthy ranges are two different approaches to the same general question, and they don't always agree exactly — which is normal. This calculator shows both together so you can see where they overlap.

Common Mistakes to Avoid

Treating any single formula's number as an exact target

Solution:

These are population-average formulas from clinical and dosing contexts, not personalized medical targets — the spread across all four formulas is itself useful information, showing the range of reasonable estimates rather than one "correct" answer.

Ignoring body frame size entirely

Solution:

The base formulas assume an average frame — if you know you have a distinctly small or large frame, apply the adjustment for a more representative estimate.

Not accounting for muscle mass or body composition

Solution:

These formulas are based purely on height and sex — an athlete with significant muscle mass will reasonably weigh more than these formulas suggest without being overweight.

Using this as a substitute for a healthcare provider's assessment

Solution:

This tool is a general reference point, not personalized medical guidance — a healthcare provider can account for muscle mass, health conditions, and individual factors these formulas can't.

Frequently Asked Questions

None of the four is definitively more accurate than the others — they're all population-average formulas developed decades ago for clinical contexts like medication dosing. That's exactly why this calculator shows all four together with their average, rather than presenting one as the single correct answer.
One of the most widely used ideal body weight formulas, originally developed in 1974 for drug dosing calculations. For men: 50 kg + 2.3 kg per inch over 5 feet. For women: 45.5 kg + 2.3 kg per inch over 5 feet.
This calculator applies a rough ±10% adjustment for a small or large frame, since the base formulas assume an average frame size. It's an estimate, not a precise measurement — if you're unsure of your frame size, medium (no adjustment) is a reasonable default.
Ideal weight formulas and BMI-based healthy ranges are two different, independently developed approaches to a similar question — they use different methods and don't always produce identical ranges. This calculator shows the BMI-healthy range alongside the four formula estimates so you can compare them directly.
No — every calculation runs locally in your browser. Nothing you enter is uploaded, logged, or stored on any server.

Free Online Ideal Weight Calculator

Estimate your ideal body weight using four long-standing clinical formulas — Devine, Robinson, Miller, and Hamwi — shown side by side rather than picking just one, since none of them is more "correct" than the others. Adjust for a small, medium, or large body frame, and see the BMI-based healthy weight range for your height as a cross-reference.

What You Get

  • Ideal weight estimates from four established formulas: Devine, Robinson, Miller, and Hamwi
  • An averaged estimate across all four
  • A body frame size adjustment (small, medium, large)
  • The BMI-healthy weight range for your height, for cross-reference
  • Support for Imperial (ft/in) or Metric (cm) units
  • No signup, no data stored — everything runs in your browser

Who Uses This Calculator

Anyone curious what a commonly cited "ideal weight" range looks like for their height — often used as a starting reference point alongside BMI, not as a strict target — uses this calculator for a quick, free estimate.