Clinical reference calculator

Glucose Infusion Rate Calculator

Calculate glucose infusion rate from dextrose concentration, infusion rate, and body weight.

Calculator inputs

Enter the available information

GIR
Calculated result

Result summary

Your result will appear here

Complete every required field, then select the calculate button.

Dextrose concentration, infusion rate, and body weight used in infusion arithmetic
All three inputs must describe the same infusion and current patient weight.

What is Glucose Infusion Rate?

The glucose infusion rate (GIR) expresses how many milligrams of glucose are delivered per kilogram of body weight each minute. It is commonly used when reviewing intravenous dextrose delivery, particularly in neonatal and pediatric care. The calculation combines solution concentration, pump rate, and weight into one weight-adjusted rate.

This page accepts dextrose concentration as percent weight per volume, infusion rate in milliliters per hour, and weight in kilograms. In this convention, D10 contains 10 grams of dextrose per 100 mL, which is 100 mg/mL.

GIR arithmetic does not determine whether an infusion is appropriate. Prescribing and changing intravenous dextrose require trained clinical oversight, confirmed solution labeling, glucose monitoring, assessment of the patient, and local protocols. A pump or line error can have serious consequences. Do not change an infusion based on this page.

How to Use This Calculator

  1. Confirm the labeled dextrose concentration and enter its percentage, such as 10 for D10.
  2. Enter the infusion pump rate in mL/hour.
  3. Enter current dosing weight in kilograms.
  4. Select Calculate and read GIR in mg/kg/min.
  5. Independently verify the units and arithmetic before any clinical use.

The fields do not accept pounds, mL/min, or a decimal fraction for concentration. Convert weight to kilograms before entry. If a solution is compounded or mixed with other fluids, verify the final concentration rather than relying only on the stock bag label.

Clinical calculations should use the weight specified by the care protocol; birth weight, current weight, dry weight, or another dosing weight may differ. The choice is a clinical decision, not something this arithmetic can resolve.

When several glucose-containing infusions run at once, the total GIR requires calculating the glucose contribution of each and summing them.

Formula Used

GIR (mg/kg/min) = dextrose (%) × rate (mL/hr) × 10 ÷ [weight (kg) × 60]

The factor 10 converts a percent weight/volume concentration into mg/mL: C grams per 100 mL equals 10C mg/mL. Dividing the hourly delivery by 60 converts hours to minutes, and dividing by kilograms makes the rate weight-adjusted.

An equivalent expanded form is [(C g/100 mL) × 1,000 mg/g × rate mL/hr] ÷ [60 min/hr × weight kg].

Variables Explained

Glucose infusion rate quantities
Input or resultRequired unitMeaning
Dextrose concentration% w/vGrams of dextrose per 100 mL of final solution.
Infusion ratemL/hrVolume delivered by the infusion each hour.
WeightkgThe dosing weight selected under the applicable clinical protocol.
GIRmg/kg/minGlucose mass delivered per kilogram each minute.

Worked Example

For D10 running at 6 mL/hour for a 3 kg patient:

GIR = 10 × 6 × 10 ÷ (3 × 60) = 600 ÷ 180 = 3.3333 mg/kg/min

A unit check reaches the same answer. D10 is 100 mg/mL. At 6 mL/hour, delivery is 600 mg/hour, or 10 mg/min. Dividing by 3 kg gives 3.3333 mg/kg/min.

For a second check, D5 at 12 mL/hour for 4 kg gives 5 × 12 × 10 ÷ (4 × 60) = 2.5 mg/kg/min. These examples demonstrate arithmetic only and are not dosing recommendations.

Why Use This Calculator?

The result is a delivery rate, not a blood glucose prediction. Blood glucose depends on endogenous production, insulin, illness, nutrition, medications, organ function, and other factors. Two patients receiving the same GIR can respond differently.

Interpretation varies by age, diagnosis, treatment goal, route, and local practice. A clinician should compare the calculated rate with the actual order, pump setting, line contents, glucose measurements, and the full care plan.

A plausible-looking number does not prove the inputs are correct. Verify the final bag concentration after additives, check whether another infusion contributes dextrose, and make sure weight and pump rate have not been copied in different units. Urgent concerns about an infusion or abnormal glucose require immediate contact with the treating team.

Common Mistakes

  • Entering 0.10 for D10 when the field expects 10%.
  • Entering weight in pounds instead of kilograms.
  • Using mL/min where the form requires mL/hour.
  • Using the stock solution concentration instead of the final mixed concentration.
  • Forgetting glucose supplied by another simultaneous infusion.
  • Using an outdated or inappropriate dosing weight.
  • Treating the result as a prescription or a predicted blood glucose.
  • Changing a pump without an authorized order and independent clinical checks.

Frequently Asked Questions

What does D10 mean in this calculation?

D10 means 10 grams of dextrose per 100 mL of final solution, equivalent to 100 mg/mL.

Can I enter weight in pounds?

No. Convert to kilograms first and verify the dosing weight required by the clinical protocol.

Does GIR predict a blood glucose value?

No. It reports glucose delivery per kilogram per minute; metabolic response depends on many clinical factors.

Should multiple dextrose infusions be combined?

Yes when calculating total delivery. Work out each glucose contribution and add them, with an independent clinical check.

Does this calculator recommend an infusion rate?

No. It only performs unit-based arithmetic from supplied values and must not be used to prescribe or change treatment.

Why is there a factor of 10 in the formula?

A C% weight/volume solution contains 10C milligrams per milliliter, so the factor converts concentration to mg/mL.

Which weight should be entered?

Use the dosing weight specified by the treating team or local protocol. The correct clinical choice may not be current scale weight.

What if the solution was compounded?

Verify the final concentration from the preparation record and label. Do not assume it remains equal to the starting stock concentration.

Sources & References