M+QuickMedCalc
Educational reference only. Not a diagnostic tool. See full disclaimer.
General MedicineIBW

Devine Ideal Body Weight Calculator for Adults

Calculate the adult Devine ideal body weight reference from height and the formula’s male or female coefficient, with kg/lb output and an input-specific formula breakdown.

Content updated: View sources

QuickMedCalc is developed and maintained by an independent developer. Medical content is not independently reviewed by a physician.

Formula and medical content are based on the references listed on this page. See sources, About, and Sources and Review Process.

Input

cm

Enter the adult height to calculate. The Devine result changes by 2.3 kg for each inch.

Select the historical coefficient required by the applicable protocol; no coefficient is assumed.

Devine formula reference weight

—

Historical Devine reference weight; not a healthy-weight target or dose

Converted reference weight

—

Historical Devine reference weight; not a healthy-weight target or dose

Input height: —

Normalized height: —

Selected historical coefficient: —

Model: Devine 1974 adult reference-weight equation

  • No actual weight is used.
  • No body composition is measured.
  • The technical input range is 60–108 inches (152.4–274.32 cm).
  • Not a personalized healthy-weight target.
  • Not a medication dose.
  • Not ventilation predicted body weight.

About

The Devine equation is a historical adult reference-weight formula published in a 1974 gentamicin case-study article. It uses only height and one of two historical coefficients; it does not use actual weight, age, frame size, muscle mass, body fat, or another body-composition measure. [1, 2]

“Ideal” is the formula's historical label, not a statement that the output is a person's ideal, healthy, nutritional, or weight-loss target. IBW is not lean body weight or fat-free mass. Older IBW formulas can produce different results and do not define one unique modern healthy weight. [2, 5, 7]

Formula

Male coefficient: Devine reference weight (kg) = 50.0 + 2.3 × [height (in) − 60] [1]
Female coefficient: Devine reference weight (kg) = 45.5 + 2.3 × [height (in) − 60] [1]
Conversions: height (in) = height (cm) ÷ 2.54; weight (lb) = weight (kg) × 2.2046226218487757
Implementation boundary: this calculator does not extrapolate below 60 inches and applies a technical upper input limit of 108 inches.

Interpretation

Historical reference weight

The result is the Devine 1974 arithmetic output for the entered height and selected historical coefficient. [1, 2]

Not a healthy-weight target

It does not diagnose underweight, overweight, or obesity; define a nutrition or weight-loss target; or measure body composition. This page does not calculate BMI. [5, 7]

Not a universal dosing weight

A drug or process may require actual, ideal, adjusted, lean, capped, BSA-based, or another weight descriptor. This page cannot select the descriptor, and its output is not a dose. [4]

Not ventilation PBW

Devine IBW and ARDSNet predicted body weight have different names, formulas, and clinical purposes. Similar numbers do not make them interchangeable. This page does not calculate tidal volume or another ventilator setting. [6]

Worked examples

5 ft baseline

Male: 50.0 + 2.3 × (60 − 60) = 50.0 kg = 110.2 lb

Female: 45.5 + 2.3 × (60 − 60) = 45.5 kg = 100.3 lb

5 ft 10 in

Male: 50.0 + 2.3 × (70 − 60) = 73.0 kg = 160.9 lb

Female: 45.5 + 2.3 × (70 − 60) = 68.5 kg = 151.0 lb

Metric equivalence

177.8 cm ÷ 2.54 = 70.0 in

These are formula examples, not personalized healthy-weight or dosing recommendations.

Why “ideal” is a historical label

Devine's formula appeared in a gentamicin article. Later historical review linked IBW equations with older height-weight rules and tables. These models are not modern body-composition measurements, and “ideal” should not be read as one weight every person ought to reach. [1, 2, 7]

What the formula does not know

This calculator does not collect:

  • actual weight
  • age
  • body frame
  • waist
  • muscle mass
  • fat mass
  • edema or fluid status
  • pregnancy status
  • diagnosis
  • medication

Two adults with the same height and selected coefficient receive the same Devine result even if their actual weight and body composition differ substantially. [4, 7]

Other IBW formulas can differ

Robinson and colleagues later developed different equations from height-weight tables. Different IBW formulas can give different values at the same height. This page runs only Devine: it does not average formulas, select a “best” formula, or present their differences as a healthy-weight range. [2, 3, 5]

Drug-dosing weight must come from the applicable rule

Weight descriptorWhat it refers to
Actual body weightThe person's measured body weight.
Ideal body weightA named height-based formula such as Devine when the rule specifies it.
Adjusted body weightA separate model combining actual weight and an IBW term.
Lean/fat-free weightA separate estimated or measured body-composition descriptor.
Body surface areaA separate height-and-weight normalization method.
Capped or protocol-specific weightA rule-defined value that must come from the applicable protocol.

These descriptors can produce different numbers, and no one descriptor applies to every drug. This calculator cannot choose a weight from obesity, kidney function, a medicine name, or a clinical condition. The applicable label or protocol determines the method. [4]

Devine IBW versus ARDSNet PBW

At 177.8 cm / 5 ft 10 in:

Male coefficients

Devine: 73.0 kg

ARDSNet: 50 + 0.91 × (177.8 − 152.4) = 73.1 kg

Female coefficients

Devine: 68.5 kg

ARDSNet: 45.5 + 0.91 × (177.8 − 152.4) = 68.6 kg

The numbers are close, but the formulas are different: Devine uses 2.3 kg/in (approximately 0.9055 kg/cm), while ARDSNet uses 0.91 kg/cm. This page does not calculate or recommend tidal volume. When a ventilation protocol requires PBW, do not substitute this page's Devine result. [6]

Height measurement and calculator boundaries

  • Use a measured height rather than a visual estimate or an outdated record.
  • Each 1-inch difference changes the Devine result by 2.3 kg.
  • This calculator does not extrapolate below 60 inches (152.4 cm).
  • 108 inches (274.32 cm) is a technical data-entry limit, not a healthy-height range.
  • The accepted 60–108 inch range does not claim clinical validation at every extreme.
  • This page is for adults and does not apply the adult equation to children.

Related calculations answer different questions

  • Adjusted Body Weight requires actual weight and an IBW term and should be used only when the applicable protocol calls for it; it is not the same result as this page.
  • Creatinine Clearance uses the separate Cockcroft–Gault estimate. Weight selection depends on the specific question and rule; this page cannot choose the weight used for CrCl.
  • Adult BMI compares actual weight with height and differs from a Devine reference weight. BMI also is not, by itself, a diagnosis or personalized target.

References

  1. McCarron MM, Devine BJ. Clinical Pharmacy: Case Studies: Case Number 25 Gentamicin Therapy. Drug Intelligence & Clinical Pharmacy. 1974;8(11):650–655. doi:10.1177/106002807400801104.
  2. Pai MP, Paloucek FP. The origin of the “ideal” body weight equations. Annals of Pharmacotherapy. 2000;34(9):1066–1069. PMID 10981254. doi:10.1345/aph.19381.
  3. Robinson JD, Lupkiewicz SM, Palenik L, Lopez LM, Ariet M. Determination of ideal body weight for drug dosage calculations. American Journal of Hospital Pharmacy. 1983;40(6):1016–1019. PMID 6869387.
  4. Pai MP. Drug dosing based on weight and body surface area: mathematical assumptions and limitations in obese adults. Pharmacotherapy. 2012;32(9):856–868. PMID 22711238. doi:10.1002/j.1875-9114.2012.01108.x.
  5. Peterson CM, Thomas DM, Blackburn GL, Heymsfield SB. Universal equation for estimating ideal body weight and body weight at any BMI. American Journal of Clinical Nutrition. 2016;103(5):1197–1203. PMID 27030535. PMCID PMC4841935. doi:10.3945/ajcn.115.121178.
  6. Acute Respiratory Distress Syndrome Network. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. New England Journal of Medicine. 2000;342(18):1301–1308. PMID 10793162. doi:10.1056/NEJM200005043421801.
  7. Chichester S, Holmes TM, Hubbard J. Ideal body weight: A commentary. Clinical Nutrition ESPEN. 2021;46:246–250. PMID 34857204. PMCID PMC8646317. doi:10.1016/j.clnesp.2021.09.746.

Related Calculators

AjBW40

Calculate fixed adult AjBW40 dosing-weight arithmetic from total body weight and either an existing or optional Devine ideal body weight, with drug- and protocol-specific limitations.

CrCl

Estimate adult Cockcroft–Gault creatinine clearance in mL/min from an explicit weight basis, without automatic weight selection or a dosing recommendation.

BMI

Calculate adult BMI from metric or US customary inputs, view the CDC adult screening category, and see the formula-derived weight span for BMI 18.5–24.9 at the entered height with non-diagnostic interpretation limits.

Disclaimer

Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.