Glucose Infusion Rate (GIR) Calculator
Calculate the glucose infusion rate in mg/kg/min from the dextrose concentration, IV fluid rate, and body weight — the standard way to express carbohydrate delivery in neonatal and parenteral care.
e.g. D10W = 10%, D12.5W = 12.5%.
How to Use This Calculator
- Enter the dextrose concentration as a percentage (e.g. 10 for D10W, 12.5 for D12.5W).
- Enter the IV fluid rate in mL/hr.
- Enter the patient's weight in kilograms.
- Read the GIR in mg/kg/min, with the grams of glucose delivered per hour.
The result is an educational estimate. Neonatal maintenance is usually 4–8 mg/kg/min; targets and changes are set by the medical team from glucose monitoring.
How Glucose Infusion Rate Is Calculated
GIR expresses how much glucose a patient receives per kilogram of body weight each minute. It standardises dextrose delivery across different fluid rates and concentrations, which matters most in neonates, where hypoglycemia and hyperglycemia are both common.
Example: D10W at 12 mL/hr in a 3.2 kg infant → (10 × 12) ÷ (6 × 3.2) = 6.25 mg/kg/min.
The constant 6 comes from converting grams per hour to milligrams per minute (× 1000 ÷ 60 ÷ 100).
Reference GIR Targets
| Context | Typical GIR (mg/kg/min) |
|---|---|
| Neonatal maintenance | 4–8 |
| Hypoglycemia management (neonate) | 8–12+ |
| Maximum oxidation (term infant) | ~12–14 |
| Adult parenteral nutrition | 2–5 |
Persistent need for high GIR to maintain glucose can indicate hyperinsulinism and warrants specialist review.
When GIR Matters & How to Adjust It
GIR is the standard way neonatal and intensive-care teams track glucose delivery, because it can be compared across patients of any size and against the body's own glucose-burning capacity.
Raising GIR safely
GIR is increased by raising the dextrose concentration or the fluid rate. There's a limit: solutions stronger than about 12.5% dextrose are too irritating for a peripheral vein and need a central line. When fluid volume is also limited, increasing concentration (via a central line) is the way to push GIR higher.
When a high GIR is a red flag
Needing a GIR above roughly 8–10 mg/kg/min just to keep glucose normal points toward hyperinsulinism — for example congenital hyperinsulinism or an infant of a mother with diabetes — and warrants specialist review. Conversely, glucose that stays high at a modest GIR may reflect stress or insufficient insulin.
Frequently Asked Questions
What is a normal glucose infusion rate?
For a newborn, maintenance GIR is usually about 4–8 mg/kg/min. Infants with hypoglycemia may need 8–12 mg/kg/min or more. Targets are set by the care team based on glucose monitoring.
How do you calculate GIR from D10 at a given rate?
Use GIR = (dextrose % × rate in mL/hr) ÷ (6 × weight in kg). For D10W at 12 mL/hr in a 3.2 kg infant, that is (10 × 12) ÷ (6 × 3.2) ≈ 6.25 mg/kg/min.
Is GIR the same as the insulin infusion rate?
No. GIR measures glucose (dextrose) delivery, not insulin. It is insulin-adjacent because clinicians balance dextrose and insulin together — for example, during DKA management or in hyperinsulinism.
Why is GIR expressed per kilogram per minute?
Per-kilogram-per-minute units let clinicians compare glucose delivery across patients of different sizes and across different fluids, and to compare it against the body's glucose oxidation capacity.
How do you increase a baby's glucose infusion rate?
By raising the dextrose concentration or the fluid rate. Because solutions stronger than about 12.5% dextrose irritate peripheral veins, higher concentrations require a central line. When the total fluid volume is capped, increasing concentration through a central line is how the team pushes GIR higher.
What GIR suggests hyperinsulinism?
A persistent need for more than about 8–10 mg/kg/min just to keep blood glucose normal is a classic sign of hyperinsulinism, such as congenital hyperinsulinism or an infant of a mother with diabetes. It should prompt specialist endocrine evaluation.
Sources
- Cornblath M, et al. Controversies regarding definition of neonatal hypoglycemia. Pediatrics.
- American Academy of Pediatrics. Postnatal glucose homeostasis in late-preterm and term infants.
Last reviewed: June 2025