IVIG Dose Calculator

Calculate total intravenous immunoglobulin (IVIG) dose and infusion volume from body weight, dosing regimen, and product concentration, with obesity-adjusted dosing weight.

Quick Facts

Core formula
Total dose (g) = dose (g/kg) x dosing weight (kg)
Infusion volume (mL) = total dose (g) / concentration (g/mL).
Common regimens
0.4-0.6 g/kg monthly, or 1-2 g/kg total
Replacement therapy vs. immunomodulatory dosing.
Obesity adjustment
Adjusted body weight above ~120% of ideal weight
AdjBW = IBW + 0.4 x (actual weight - IBW).

Your Results

Calculated
Total IVIG dose
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Dose (g/kg) x dosing weight
Total infusion volume
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Based on product concentration
Dosing body weight used
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Actual or obesity-adjusted weight
Per-day dose / volume
-
Total split across infusion days

Ready

Enter body weight, height, sex, regimen, and concentration, then calculate.

About the IVIG dose formula

Intravenous immunoglobulin (IVIG) is dosed by body weight, similar to many weight-based infusions. The total dose in grams equals the prescribed dose in grams per kilogram multiplied by the patient's dosing body weight in kilograms. Common regimens include 0.4 to 0.6 g/kg given every 3 to 4 weeks for antibody replacement therapy, and 1 to 2 g/kg given as a total immunomodulatory dose, typically split over one to five infusion days depending on tolerability.

Choosing the dosing body weight

Immunoglobulin distributes through plasma and lean tissue rather than fat, so using actual body weight for an obese patient can push the dose - and the infused volume - higher than needed. A widely used approach is to calculate ideal body weight (IBW) with the Devine formula (50 + 2.3 kg per inch over 5 feet for men, 45.5 + 2.3 kg per inch over 5 feet for women) and, when actual weight exceeds about 120% of IBW, switch to an adjusted body weight: IBW + 0.4 x (actual weight - IBW). Otherwise, actual body weight is used directly.

From dose to infusion volume

IVIG products are supplied at a labeled concentration, commonly 5%, 10%, or 20% (grams of immunoglobulin per 100 mL of solution). Dividing the total dose in grams by the concentration expressed as grams per mL gives the total infusion volume in mL. When a dose is split across multiple infusion days, both the dose and the volume are divided evenly across those days.

Important disclaimer

This tool performs the standard weight-based dosing arithmetic for education and planning; it does not constitute medical advice and does not select a regimen for any individual patient. Actual prescribing must come from a licensed clinician or pharmacist who accounts for the diagnosis, renal function, infusion tolerance, premedication needs, and product-specific labeling.

Frequently Asked Questions

How is the total IVIG dose calculated?
Total IVIG dose in grams equals the prescribed dose in grams per kilogram multiplied by the dosing body weight in kilograms. Common regimens are 0.4 to 0.6 g/kg for replacement therapy given every 3 to 4 weeks, or 1 to 2 g/kg as a total immunomodulatory dose split over one to five days.
Why does the calculator sometimes use an adjusted body weight instead of actual weight?
Immunoglobulin distributes mainly in plasma and lean tissue, not fat, so dosing obese patients on actual body weight can overshoot the effective dose and raise the risk of volume-related side effects. When actual weight exceeds about 120 percent of ideal body weight (Devine formula), many protocols use an adjusted body weight of ideal weight plus 40 percent of the excess weight instead.
How is the infusion volume calculated from product concentration?
IVIG products are labeled by concentration, such as 5, 10, or 20 grams per 100 mL. Dividing the total dose in grams by the concentration expressed as grams per mL gives the total infusion volume in mL, which can then be divided across the planned number of infusion days.

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