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Adjusted Body Weight Calculator

Compute Devine ideal body weight and adjusted body weight from sex, height, and total body weight. When total weight is above IBW, ABW = IBW + 0.4 × (TBW - IBW). Informational, not a prescription.

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How to calculate adjusted body weight

  1. Choose metric or US units so height and weight fields match.
  2. Select the sex the Devine formula should use.
  3. Enter height and total body weight.
  4. Read IBW, ABW, and whether ABW equals TBW because weight is at or under IBW.
  5. Compare with ideal-weight and BMI pages when you need other frames. Nothing is uploaded.

Adjusted body weight

Devine IBW with 0.4 excess factor

Male Devine IBW50 kg + 2.3 kg per inch over 5 ft
Female Devine IBW45.5 kg + 2.3 kg per inch over 5 ft
ABW when TBW > IBWIBW + 0.4 × (TBW - IBW)
When TBW ≤ IBWABW equals total body weight
InputsSex, height, total body weight
AdviceInformational. Not a medication order.

What adjusted body weight is

Adjusted body weight blends ideal and total mass when someone weighs more than a Devine ideal. Pharmacists and educators often use it as a teaching estimate for certain dosing discussions. This page only performs the arithmetic; it does not choose a drug or a dose.

How IBW and ABW are built

Devine IBW uses 50 kg (male) or 45.5 kg (female) plus 2.3 kg for each inch of height above 60 inches. If total body weight exceeds IBW, ABW = IBW + 0.4 × (TBW - IBW). If total weight is at or under IBW, ABW equals total weight.

IBW, ABW, BMI, and surface area

Entities include Devine IBW, adjusted body weight, and excess mass. Multiple named ideals live on ideal weight. Mass over height squared is BMI. Dosing-adjacent surface area is BSA.

Use cases

Homework that asks for Devine IBW and a 0.4 adjusted weight. Comparing TBW with ABW before a class discussion. Cross-checking another calculator that cites the same factor. Not a substitute for a pharmacist or clinician order.

Default numbers

Male, 175 cm (about 68.9 in), 90 kg: inches over 60 ≈ 8.9, so IBW ≈ 50 + 2.3 × 8.9 ≈ 70.4 kg. Excess ≈ 19.6 kg, so ABW ≈ 70.4 + 0.4 × 19.6 ≈ 78.3 kg.

Limits

Some references use factors other than 0.4. Pediatric, critically ill, and specialty dosing rules are out of scope. Informational only. See the disclaimer. CZNull does not receive the measurements.

Adjusted body weight questions

What is the 0.4 factor?
A common teaching default that adds 40% of the weight above Devine IBW. Protocols can use other factors; this page defaults to 0.4.
What if I weigh less than IBW?
Adjusted weight equals total body weight. No excess term is added.
Is Devine the only ideal formula?
No. Robinson, Miller, and Hamwi appear on the ideal weight page. This tool sticks to Devine for ABW.
Can I use this to dose medicine?
No. Dosing requires a licensed professional, the drug label, and clinical context this form does not have.
Why ask for sex?
Devine male and female bases differ (50 kg versus 45.5 kg) before the height term.
Does the page upload height or weight?
No. IBW and ABW are computed in this tab only.