IVIG Dose Calculator
Calculate IVIG dose by weight using ideal body weight, BMI, and dosing rate. Free IVIG and RhIG dosing calculator for healthcare professionals with breakdowns and charts.
About This Calculator
The IVIG Dose Calculator helps healthcare professionals determine the appropriate dose of intravenous immunoglobulin (IVIG) for patients based on their weight, height, sex, and the prescribed dosing rate. It also supports Rh(D) immune globulin dose calculation for preventing hemolytic disease of the fetus and newborn in Rh-negative mothers.
IVIG (intravenous immunoglobulin) contains antibodies that help patients with compromised immune systems fight infections and manage autoimmune conditions. Accurate dosing is critical — underdosing may fail to provide therapeutic benefit, while overdosing increases the risk of adverse effects including renal failure, thrombosis, and aseptic meningitis.
How IVIG Dose is Calculated
For non-obese patients (BMI < 30), the calculator uses the Devine formula to determine ideal body weight (IBW). If the patient's actual weight is lower than IBW, actual weight is used instead to avoid overdosing. For obese patients (BMI ≥ 30), an adjusted (dosing) body weight is calculated: IBW + 0.5 × (actual weight − IBW). The final IVIG dose = dosing rate (g/kg) × dosing weight (kg).
Rh(D) Immune Globulin Dosing
For Rh-negative mothers carrying an Rh-positive fetus, RhIG (RhoGAM) is administered to prevent maternal sensitization. The required dose depends on the volume of fetal-maternal hemorrhage, estimated from the percentage of fetal cells in maternal blood (measured via Kleihauer-Betke test or flow cytometry) and maternal blood volume (calculated using Nadler's formula). The calculator determines how many 300 µg (1500 IU) vials are needed.
Regional Notes
India: IVIG brands include Bharat Immunologicals and Intas. Dosing follows international guidelines. The cost of IVIG in India ranges from ₹3,000–₹8,000 per gram depending on the brand and hospital.
United States: IVIG is FDA-approved for PID, CIDP, ITP, Kawasaki disease, and Guillain-Barré syndrome. Common brands include Privigen (CSL Behring), Gammagard (Takeda), and Octagam (Octapharma). RhIG is administered as RhoGAM or HyperRHO at 300 µg per vial.
United Kingdom: NHS guidelines recommend IVIG for CIDP, Guillain-Barré syndrome, and PID. RhIG is routinely offered to all RhD-negative women after sensitizing events and at 28 weeks gestation. Brands include Kiovig (Takeda) and Octagam.
Frequently Asked Questions
How is IVIG dose calculated?
IVIG dose is calculated by multiplying the dosing rate (g/kg) by the patient's dosing weight. For non-obese patients (BMI < 30), the ideal body weight from the Devine formula is used unless actual weight is lower. For obese patients (BMI ≥ 30), an adjusted body weight is used: IBW + 0.5 × (actual weight − IBW).
What is the Devine formula for ideal body weight?
The Devine formula for ideal body weight is: For women — 45.5 kg + 2.3 kg for every inch over 5 feet (60 inches). For men — 50.0 kg + 2.3 kg for every inch over 5 feet. Height must first be converted from centimeters to inches by dividing by 2.54.
What is a typical IVIG dosing rate?
Typical IVIG dosing ranges from 1 to 2 g/kg depending on the condition. For Chronic Inflammatory Demyelinating Polyneuropathy (CIDP), 2 g/kg is commonly used as a loading dose. For Primary Immunodeficiency (PID), 0.4–0.6 g/kg every 3–4 weeks is standard. For Kawasaki disease, a single dose of 2 g/kg is given.
How is RhIG dose calculated for maternal-fetal hemorrhage?
RhIG dose is calculated using the formula: RhIG dose = (Fetal cells % × Maternal blood volume / 30) + 1, rounded up to the nearest whole vial. Each vial contains 300 µg (1500 IU) of Rh(D) immune globulin. Maternal blood volume is estimated using Nadler's formula for women.
What is maternal blood volume and how is it calculated?
Maternal blood volume is estimated using Nadler's formula for females: Blood volume (mL) = (356.1 × height in meters³) + (33.08 × weight in kg) + 183.3. This formula accounts for the mother's height and weight to estimate total circulating blood volume for RhIG dosing calculations.
When should I use actual weight instead of ideal body weight for IVIG?
You should use actual weight instead of ideal body weight when the patient's actual weight is lower than their calculated ideal body weight. This prevents overdosing in underweight patients. For obese patients (BMI ≥ 30), an adjusted body weight (IBW + 0.5 × excess weight) is used instead of either actual or ideal weight.
Is IVIG dosing the same in India, US, and UK?
The weight-based IVIG dosing formula is the same worldwide. However, product availability, brand names, and infusion protocols vary by region. In India, common brands include Bharat Immunologicals and Intas products. In the US, brands include Privigen, Gammagard, and Octagam. In the UK, brands include Kiovig and Octagam. Always follow local clinical guidelines.
What conditions require IVIG treatment?
IVIG is used for primary immunodeficiency disorders, autoimmune diseases such as Guillain-Barré syndrome and CIDP, Kawasaki disease, immune thrombocytopenia (ITP), certain cases of leukemia and bone marrow transplant, HIV/AIDS complications, and multifocal motor neuropathy. Each condition has specific dosing protocols.