Introduction
The Glucose Infusion Rate (GIR) Calculator shows how much sugar a patient gets from IV fluids. It reports the answer in mg/kg/min, which is the standard way doctors and nurses check dextrose dosing. This tool is used most often for babies in the NICU, but it works for children and adults too.
Enter the patient's weight, then add the rate for each dextrose line. You can use up to three streams at once: D5W, D10W, and one custom bag such as TPN, D12.5W, or D15W. The calculator adds them all together and gives you one total GIR. If you also need to set the pump itself, pair this with our IV Infusion Rate Calculator or the Infusion Drip Calculator.
You get these results right away:
- GIR for each line and the combined total
- Total dextrose in grams per hour and grams per day
- Total fluid rate and fluid per kilogram per day
- A range check that flags low, normal, high, or very high GIR
- A step-by-step solution, a full table, and charts
You can pick your own units. Weight can be kg, pounds, or grams. Rates can be mL/hr, mL/min, L/hr, or mL/day. Results can show as mg/kg/min, mcg/kg/min, mg/kg/hr, or g/kg/day. This helps you avoid math errors when orders are written in different units. For quick weight conversions on their own, try the Pounds to Kilograms Calculator or the Kg to Lbs Calculator.
Use this calculator as a quick check, not as a substitute for clinical judgment. Always confirm doses with your own hospital protocol and pharmacy team.
How to use our Glucose Infusion Rate (GIR) Calculator
Enter the patient's weight and the rate of each dextrose drip. The calculator shows the GIR for each line, the total GIR, the grams of dextrose given per day, and the total fluid rate, plus a step-by-step solution and charts.
Body Weight: Type the patient's dosing weight. The tool checks that the weight is between 0.2 kg and 400 kg. For adult dosing weights, the Adjusted Body Weight Calculator and Ideal Body Weight Calculator can help you choose the right number.
Weight Unit: Pick kg, lbs, or grams. The calculator changes your number to kilograms and shows it below the buttons.
Report GIR In: Choose the unit for your answers: mg/kg/min, mcg/kg/min, mg/kg/hr, or g/kg/day. Target range numbers change to match. Our Unit Converter Calculator handles other conversions you may need at the bedside.
Stream 1 — D5W Infusion Rate: Type the pump rate for the 5% dextrose line and pick its unit (mL/hr, mL/min, L/hr, or mL/day). Leave it blank or 0 if this line is off. The 5% strength is fixed.
Stream 2 — D10W Infusion Rate: Type the pump rate for the 10% dextrose line and pick its unit. Leave it blank or 0 if this line is off. The 10% strength is fixed.
Stream 3 — Dextrose Concentration: Type the strength of your custom fluid, like TPN, D12.5W, or D15W. Pick % (g/dL), g/L, or mg/mL. If you are mixing a bag down from a stronger stock solution, the Dilution Calculator is a useful companion.
Stream 3 — Custom Infusion Rate: Type the pump rate for that custom line and pick its unit. Leave it blank if the line is not running.
Calculate and Reset: Press Calculate to see your results. Press Reset to clear every field and start over.
What Is Glucose Infusion Rate (GIR)?
Glucose infusion rate, or GIR, tells you how fast sugar (dextrose) is going into a patient through an IV line. It is measured in milligrams of sugar per kilogram of body weight each minute — written as mg/kg/min. Because the number is based on body weight, a tiny newborn and a grown adult can be compared using the same scale.
Why GIR Matters
GIR is used most often in newborn and pediatric care. Babies have small sugar stores, so they can drop low fast. Doctors and nurses track GIR to keep blood sugar steady, treat low blood sugar (hypoglycemia), and give enough calories. Too little sugar can cause low blood sugar. Too much sugar can cause high blood sugar, extra fat in the liver, or too much carbon dioxide from the body burning sugar. For longer-term glucose control, clinicians often look at trends with an A1C Calculator.
How GIR Is Figured Out
GIR depends on three things: the strength of the dextrose fluid, how fast the fluid runs, and the patient's weight.
GIR (mg/kg/min) = dextrose % × rate (mL/hr) × 1000 ÷ (weight in kg × 60 × 100)
The 1000 changes grams into milligrams. The 60 changes hours into minutes. The 100 changes percent (g/dL) into g/mL. If you want to review the percentage step on its own, our Percentage Calculator walks through it.
Common Dextrose Fluids
- D5W — 5% dextrose, or 5 grams of sugar in every 100 mL.
- D10W — 10% dextrose, often the first choice for newborns.
- D12.5W and higher — stronger mixes. Anything above about 12.5% usually needs a central line, since strong sugar can hurt small veins.
- TPN — IV nutrition that also carries dextrose and adds to the total GIR.
Adding Up More Than One Line
Many patients get sugar from more than one IV at the same time. Each line has its own GIR, and the total GIR is all of them added together. This is why a patient can be getting far more sugar than any single line shows. Always add every line that carries dextrose, including weight-based drips you may be checking with the Heparin Drip Calculator or a general Flow Rate Calculator.
Typical Target Ranges
These numbers are general guides, not orders. Every patient is different.
- Under 5 mg/kg/min — usually too low for a newborn who is not feeding.
- 5–8 mg/kg/min — the common starting range for newborns.
- 8–14 mg/kg/min — higher than usual. Watch blood sugar closely.
- Over 14 mg/kg/min — near the top limit for how fast the body can use sugar. Risk of high blood sugar rises.
Adults on IV nutrition are usually kept near or below about 4–5 mg/kg/min. Adult dosing checks often use body surface area from the BSA Calculator, while growth tracking in infants is easier with the Baby Weight Percentile Calculator or the Baby Percentile Calculator.
Other Ways GIR Is Written
The same rate can be shown in different units. 1 mg/kg/min equals 1,000 mcg/kg/min, 60 mg/kg/hr, or about 1.44 g/kg/day. The g/kg/day form is handy when checking total calories from IV nutrition, which you can compare against targets from the Calorie Calculator or the Carb Calculator.
Things To Watch
Use the patient's real dosing weight, and update it as the weight changes. Remember that total fluid matters too, not just sugar — a high GIR often means a lot of fluid, so review intake and output alongside the Urine Output Calculator and lab values such as those from the Serum Osmolality Calculator or Anion Gap Calculator. Check blood sugar often after any rate or strength change, and confirm kidney function with the GFR Calculator when fluid loads are high. GIR math is a helper for care, not a replacement for a clinician's judgment.