Gives ideal body weight by the Devine formula from height and sex and, with the actual weight, the adjusted body weight and the percentage of ideal weight.
Result
Choose the sex and enter the height.
Sources
3 studies
3
studies
389
citations
3,875
PubMed papers
Evidence
Known limitations
A history of the ideal body weight equations: Devine’s 1974 formula for drug dosing matched an old rule of thumb from height-weight tables, and later regression equations came out similar because the tables they were fitted to agree.
Ann Pharmacother: Journal Metrics Score 1.6, Q2 · cited 389 times
In 861 patients with acute lung injury and ARDS, lower tidal volumes lowered mortality compared with traditional volumes (31.0% vs 39.8%). Both arms set tidal volume per kilogram of predicted body weight, which is nearly the Devine line written in centimeters.
N Engl J Med: Journal Metrics Score 29.8, Q1 · cited 13,100 times
In 3,678 patients, the Cockcroft-Gault equation was least biased with actual weight in underweight patients, ideal weight at normal weight, and adjusted weight (factor 0.4) in overweight and obese patients, showing how the choice of weight changes a weight-based estimate.
Pharmacotherapy: Journal Metrics Score 2.4, Q1 · cited 201 times
The key paper has been cited 389 times, and 3,875 PubMed articles mention ideal, adjusted or predicted body weight in their title or abstract. Citation counts from OpenAlex and article counts from PubMed, retrieved November 12, 2026. Journal Metrics Scores and quartiles are from this site’s current release; follow the journal name for details.
After the result
Actual weight well above ideal · Actual weight below ideal · Any result
Check which weight each protocol uses. Ideal weight overstates body mass. Measure height and weight.
Next steps
Avoid common errors
4 common errors to avoid
and 2 more
When the estimate misleads
1Estimated height
Each inch of height changes the ideal weight by 2.3 kg. Measure height, or use a validated substitute such as ulna length, in patients who cannot stand.
2Short stature
Below 5 feet the formula is extrapolated and can give implausibly low weights.
3Not a healthy weight target
Ideal body weight is a calculation reference for dosing and ventilation, not a goal weight for the individual.
4Amputation and edema
Fluid overload raises actual weight without changing the reference weights. After a limb amputation, ideal weight from height overstates the reference weight; references reduce it by the proportion of body weight the missing limb represents.
Formula
Ideal body weight = 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 feet; adjusted = ideal + 0.4 × (actual − ideal).
50 / 45.5 + 2.3 kg per inch over 5 ft
Ideal body weight = 50 kg (men) or 45.5 kg (women) + 2.3 kg per inch over 5 feet; adjusted = ideal + 0.4 × (actual − ideal).
Formulas and reference values
| Weight | Formula |
|---|---|
| Ideal body weight (Devine) | men 50 kg, women 45.5 kg, + 2.3 kg per inch over 5 feet |
| Adjusted body weight | ideal + 0.4 × (actual − ideal), when actual is above ideal |
| Predicted body weight (ARDS Network) | men 50, women 45.5, + 0.91 × (height in cm − 152.4) |
| Height | Men | Women |
|---|---|---|
| 5 ft 0 in (152.4 cm) | 50.0 kg | 45.5 kg |
| 5 ft 4 in (162.6 cm) | 59.2 kg | 54.7 kg |
| 5 ft 8 in (172.7 cm) | 68.4 kg | 63.9 kg |
| 6 ft 0 in (182.9 cm) | 77.6 kg | 73.1 kg |
Devine 1974
The 0.4 factor
ARDS Network
Test cases
3 published cases, each also a test case
3 published cases; the calculator reproduces every result.
Worked examples
A 57-year-old woman with obesity weighed 80 kg at a height of 1.57 m (BMI 32.5) and received a weight-based medicine on her actual weight before developing kidney injury. The authors give her ideal body weight for height as 49.7 kg by Devine’s formula.
“Her ideal body weight for height was 49.7 kg using Devine’s formula”
Her adjusted weight is 61.8 kg. The second patient in the same report, a man of 1.73 m, has an ideal weight of 68.7 kg, as the authors state.
Entered as: Sex: Female; Height: 157 cm; Actual body weight: 80 kg.
Source: Lim APW et al., Cureus 2024 (PubMed · Free full text · DOI)
A 20-year-old man of 165 cm, who weighed 510 kg after months of in-hospital weight loss, had a laparoscopic sleeve gastrectomy. The anesthetic team recorded an ideal body weight of 61.4 kg and an adjusted body weight of 240.8 kg.
“ideal body weight (IBW) 61.4 kg, adjusted body weight 240.8 kg”
Both of the reported weights match: 61.4 + 0.4 × (510 − 61.4) = 240.8 kg.
Entered as: Sex: Male; Height: 165 cm; Actual body weight: 510 kg.
Source: Terkawi AS et al., Saudi J Anaesth 2014 (PubMed · Free full text · DOI)
An 86-year-old man of 154.7 cm who weighed 34.7 kg had a giant bulla in the right lung and underwent laparoscopic surgery for sigmoid colon cancer. The report gives an ideal body weight of 52 kg.
“154.7 cm, 34.7 kg, ideal body weight 52 kg”
The report gives 52 kg without naming the formula; Devine gives 52.1 kg, which rounds to 52 kg. His actual weight is 67% of ideal, so there is no adjusted weight.
Entered as: Sex: Male; Height: 154.7 cm; Actual body weight: 34.7 kg.
Source: Lee SH et al., AME Case Rep 2026 (PubMed · Free full text · DOI)
FAQ
7 questions and answers
and 5 more answers
Questions
With the Devine formula: 50 kg for men or 45.5 kg for women, plus 2.3 kg for every inch of height over 5 feet. A man of 5 feet 10 inches (177.8 cm) has an ideal body weight of 50 + 2.3 × 10 = 73 kg; a woman of 5 feet 4 inches (162.6 cm) has 45.5 + 2.3 × 4 = 54.7 kg.
Adjusted body weight = ideal body weight + 0.4 × (actual weight − ideal body weight). The calculator gives it whenever actual weight is above ideal weight; references differ on the threshold at which they use it (often 120% or 130% of ideal). A man with an ideal weight of 73 kg who weighs 120 kg has an adjusted weight of 73 + 0.4 × 47 = 91.8 kg.
They are nearly the same line written differently. The ARDS Network trial wrote predicted body weight in centimeters as 50 (men) or 45.5 (women) + 0.91 × (height in cm − 152.4). Because 2.3 kg per inch is 0.906 kg per cm, the two differ by at most a few tenths of a kilogram.
Devine published it in 1974 for drug dosing. Pai and Paloucek (2000) found it consistent with an older rule of thumb from height-weight tables, and found that the later Robinson and Miller regression equations came out similar because the tables agree. The equations still differ somewhat at the extremes of height.
The formula was written for adults of 5 feet (152.4 cm) or taller. Below that, extending the line subtracts 2.3 kg per inch, which quickly gives very low weights; some references use a fixed minimum instead. The calculator extends the line and warns.
Adjusted weight applies only to excess weight, so it is not calculated. For weight-based drug calculations and creatinine clearance, many references use actual weight when it is below ideal weight. Ventilator tidal volumes still use predicted body weight, whatever the actual weight.
It depends on the drug or protocol, not on the formula. Ventilator tidal volumes are usually set per kilogram of predicted body weight, and drug labels and local guidance say whether to use actual, ideal or adjusted weight. This page gives the weights only.
Further reading
6 references with PubMed and DOI links
6
references
3
free full text
From Pai MP et al., Ann Pharmacother 2000 to the newest case reports.
References
Contributed by Dr. Meng Zhao (MD · Former Neurosurgeon · Medical AI Researcher), from the original publications listed here. Last updated November 12, 2026. LinkedIn
The calculator code is tested against every worked example on this page before each release.
This calculator supports, and does not replace, clinical judgment. It is meant for healthcare professionals and is not medical advice for patients. Report an error through the contact page.
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Which uses actual, ideal or adjusted weight.
Another weight-based estimate.
Which published the history of the ideal body weight equations, with its current metrics.