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Ideal Weight Calculator

There is no single ideal weight — this calculator averages three published estimating formulas (Devine, Robinson, and Miller) that each predict body weight from height and sex by adding a fixed amount per inch over 5 feet to a base weight. The formulas were built for drug dosing and clinical reference, not aesthetics, so read the result as a reference range rather than a target.

Ideal weight
71.6
kg
Devine
73.2
kg
Robinson
71.1
kg
Miller
70.4
kg
Your ideal-weight range is about 70.4–73.2 kg
The Devine, Robinson, and Miller formulas center near 71.6 kg but are height-only by design — treat the range as a reference, not a target.
Inputs
A who is cm tall
'Ideal weight' is a range, not a target
The three formulas differ by several kilograms for the same height, which is why we show a spread. Landing exactly on the average isn't the goal.
Height-only, by design
Devine (1974) began as a drug-dosing formula. These ignore frame size, muscle, and age, so treat the range as a rough reference and cross-check with BMI or body fat.
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Uses your inputs above
71.6 ideal weight. Want to try a variation?

The math

Reviewed 2026
Formula
Devine M: 50 + 2.3·(in over 5ft); F: 45.5 + 2.3·(in over 5ft)

Related calculators

BMI
Body fat

Example: how ideal weight is calculated

Step-by-step with default inputs

Suppose you put the default values into Ideal Weight Calculator:

Sex
Male
Height (cm)
178

Plug those into the formula Devine M: 50 + 2.3·(in over 5ft); F: 45.5 + 2.3·(in over 5ft) and the result is:

Ideal weight
71.6

How to calculate ideal weight by hand

  1. Convert height to inches (heightCm / 2.54) and subtract 60 to get inches over 5 ft (use 0 if negative).
  2. Devine: start at 50 kg for men or 45.5 kg for women and add 2.3 kg per inch over 5 ft.
  3. Robinson: start at 52 kg (add 1.9/inch) for men or 49 kg (add 1.7/inch) for women.
  4. Miller: start at 56.2 kg (add 1.41/inch) for men or 53.1 kg (add 1.36/inch) for women.
  5. Average the three results for the headline ideal weight in kg.

How does the ideal weight calculator work?

The headline number is the average of three height-based formulas. Devine (1974) — 50 kg + 2.3 kg per inch over 5 ft for men, 45.5 kg base for women — was created to standardize drug dosing, is the calculator's cited reference, and remains the clinical default. Alongside it the calculator averages in two later refinements that keep the same structure but use different bases and per-inch slopes (52 kg + 1.9 and 56.2 kg + 1.41 for men, respectively); these are rules of thumb this calculator adopts, not figures drawn from its cited source. All three ignore frame size, muscularity, age, and body composition entirely, and all flatten to their base weight below 5 ft. The spread between them is a built-in reminder of how approximate any height-only weight estimate is.

References: Devine formula (1974).

Last reviewed July 2, 2026 · Editorial policy

Frequently asked questions

Why do the three formulas disagree?

Each was fit with different base weights and per-inch slopes. At the default 178 cm male height they span 70.4 kg (Miller) to 73.2 kg (Devine) — about a 3 kg spread — and the gap widens with height. Averaging smooths out individual formula quirks.

Is ideal weight the same as a healthy weight?

No — these formulas predict a single reference weight from height alone, and were originally built for drug-dose calculations. A healthy weight is better thought of as a range shaped by body composition and frame; the BMI calculator gives that range-based view.

What happens if I'm shorter than 5 feet?

The formulas simply return their base weights (45.5 to 56.2 kg depending on formula and sex), because the per-inch term only counts inches above 5 ft and is floored at zero. That flattening below 5 ft is a known weak spot of these equations.

How accurate is this ideal weight calculator?

The math is deterministic — the same inputs always produce the same output, and the formula is shown above. Accuracy of the answer for your situation depends on how well your inputs match reality and how well the formula models the question.

Is this a substitute for medical advice?

No. Health calculators give informational baselines from published formulas. For decisions about your body, talk to a clinician.

How do I share my result?

Hit Share at the top of the page. Every input you change is encoded in the URL, so a permalink reproduces exactly what you see. No account needed.