How is ideal body weight calculated?

By the Devine formula: 50 kg for men or 45.5 kg for women for the first 60 inches of height, plus 2.3 kg for each inch above 60. The tool accepts height in centimetres or feet and inches.

What is adjusted body weight?

Adjusted body weight = ideal body weight + 0.4 × (actual weight − ideal weight). It is conventionally used only when actual weight exceeds ideal by roughly 20–30%. The tool shows it when you enter an actual weight.

Which weight should I use for drug dosing?

That depends on the medication — some dose by ideal, some by adjusted, some by actual weight. The tool outputs the weights only and does not tell you which to use; confirm against your own drug reference or pharmacy.

Is the Devine formula accurate?

It is an empiric estimate with no firm population basis, and it has low validity below about 5 feet of height. Treat it as a reference figure, not a precise measurement.

Does any of the data I enter leave my browser?

No. The calculation runs entirely in your browser; nothing you enter is sent to a server or stored. The print option produces a clean worksheet you can save as a PDF.

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Ideal & adjusted body weight calculator

Compute the Devine ideal body weight from sex and height, and the adjusted body weight when an actual weight is supplied. A reference-weight calculator, not a dosing tool — it outputs a weight, never a drug or dose — and nothing you enter leaves your device.

Sex

Height unit

Height (cm)

Actual weight (kg) — optional

Supply an actual weight to also see adjusted body weight. Leave it blank for ideal body weight only.

Reference weights

Ideal body weight (Devine)65.9 kg

Reference-weight calculator — not a dosing tool. It reproduces the published Devine (1974) arithmetic from the sex, height, and weight you enter, entirely in your browser (nothing is sent to a server). It outputs a WEIGHT, never a drug, dose, maximum, or frequency. It does NOT tell you which weight to dose by: some medications dose by ideal body weight, some by adjusted, some by actual — confirm the correct dosing weight against your own drug reference or pharmacy. The Devine equation is an empiric estimate with no firm population basis, and is of low validity below about 5 feet of height; conventions for when to use ideal vs adjusted vs actual weight vary by indication and guideline.

Privacy: Runs entirely in your browser — nothing you enter is sent to a server or stored.

Formulae reproduced from: ClinCalc — Ideal, Adjusted, and Nutritional Body Weight Calculator (reproduces the Devine 1974 IBW formula and the 0.4 adjusted-weight factor)..

How ideal and adjusted body weight are calculated

Ideal body weight is an empiric reference figure from a person's sex and height — the Devine equation starts at 50 kg (men) or 45.5 kg (women) for the first 5 feet and adds 2.3 kg per inch above that. Adjusted body weight blends ideal and actual weight (ideal + 0.4 × the excess) and is used for some calculations in patients well above their ideal weight. Both are reference weights, not dosing instructions — which weight to use depends on the indication and the drug reference.

Many teams still work these out on a calculator at the bedside. If you run a clinic on Avinya Plus, the same arithmetic can live on the note: our clinical templates in the EMR let you build height and weight into a form and compute ideal and adjusted body weight with the formula engine, so the figures sit beside the examination. The arithmetic is the engine's; the dosing decision stays yours.

Frequently asked questions

How is ideal body weight calculated?: By the Devine formula: 50 kg for men or 45.5 kg for women for the first 60 inches of height, plus 2.3 kg for each inch above 60. The tool accepts height in centimetres or feet and inches.
What is adjusted body weight?: Adjusted body weight = ideal body weight + 0.4 × (actual weight − ideal weight). It is conventionally used only when actual weight exceeds ideal by roughly 20–30%. The tool shows it when you enter an actual weight.
Which weight should I use for drug dosing?: That depends on the medication — some dose by ideal, some by adjusted, some by actual weight. The tool outputs the weights only and does not tell you which to use; confirm against your own drug reference or pharmacy.
Is the Devine formula accurate?: It is an empiric estimate with no firm population basis, and it has low validity below about 5 feet of height. Treat it as a reference figure, not a precise measurement.
Does any of the data I enter leave my browser?: No. The calculation runs entirely in your browser; nothing you enter is sent to a server or stored. The print option produces a clean worksheet you can save as a PDF.

Sources

ClinCalc — Ideal, Adjusted, and Nutritional Body Weight Calculator (reproduces the Devine 1974 IBW formula and the 0.4 adjusted-weight factor).

The ideal body weight formula is the Devine (1974) equation and the adjusted body weight uses the conventional 0.4 correction factor, as reproduced by ClinCalc. The Devine equation is an empiric estimate; adjusted body weight is conventionally applied only when actual weight exceeds ideal by roughly 20–30%. Reviewed against the source on 2026-06-29.

Keep reference weights on the record.

In Avinya Plus you can build height and weight into a template and let the formula engine compute ideal and adjusted body weight automatically — the dosing decision stays with you. See it on a quick demo.