Intravenous immunoglobulin (IVIG) is dosed very differently depending on why it's being given — a monthly antibody-replacement infusion for immunodeficiency looks nothing like a single 2 g/kg loading dose for Kawasaki disease. This calculator converts body weight, an indication-based dose rate, and a day count into a total course dose, an infusion volume, and general infusion-rate guidance.
How IVIG dosing is calculated
The core formula is simple: total dose (g) = weight (kg) × dose rate (g/kg/day) × number of days. What makes IVIG dosing complex is that the dose rate and day count vary widely by indication. Primary immunodeficiency is typically replaced with 0.4-0.6 g/kg roughly every 3-4 weeks, given as a single infusion per cycle. Kawasaki disease uses a single 2 g/kg infusion, usually given over 10-12 hours. ITP is typically dosed at 1 g/kg/day for 1-2 days. Guillain-Barré syndrome, CIDP loading, and myasthenia gravis exacerbations commonly use 0.4 g/kg/day for 5 days — a divided regimen that totals 2 g/kg over the course.
This calculator pre-fills a typical dose rate and day count for each indication, but both fields stay editable so you can match the exact order written by the prescriber.
From dose to infusion volume
IVIG products are supplied as ready-to-infuse liquid solutions at a stated concentration — most commonly 5% (50 mg/mL) or 10% (100 mg/mL). The Infusion Volume tab converts the gram dose into milliliters by dividing by the concentration: a 10% product needs half the volume of a 5% product for the same gram dose. Most current U.S.-licensed IV IVIG products (e.g. Privigen, Gammagard Liquid, Gamunex-C, Panzyga) ship at 10%, but always confirm the concentration on the actual product label before infusing.
Infusion rate and limits of this tool
IVIG is infused at a conservative starting rate — commonly 0.5-1 mL/kg/hr for the first 15-30 minutes — then increased stepwise if tolerated, typically up to a product-specific maximum of 3-6 mL/kg/hr. The Rate Guidance Note tab gives this general schedule and an estimated minimum infusion time, but it is not a substitute for the exact titration schedule in the current prescribing information for the specific product being used.
This calculator is a reference dose and volume estimate only, not a prescription. The decision to give IVIG at all, the exact dose, the product, and the infusion rate are clinical decisions made by the treating clinician and pharmacist, accounting for the patient's renal function, cardiovascular status, IgA levels (for anaphylaxis risk), and institutional protocol. In patients with obesity, some clinicians dose using adjusted or ideal body weight rather than actual weight to reduce the risk of hyperviscosity-related adverse events such as hemolysis or thrombosis — this calculator uses actual body weight and does not make that adjustment automatically.