Blood glucose unit:

mg/dL

mg/dL * typical target: 80-120

mg/dL drop per unit

grams * enter 0 for correction only

1 unit covers g carbs

Leave at 0 if eating no carbs

Fill in your blood glucose values and correction factor above to calculate your dose.

Mealtime insulin dose has two components - a correction portion (to bring elevated blood glucose down to target) and a food portion (to cover the carbohydrates you're about to eat):

Correction Dose = (Current BG - Target BG) / Correction Factor Food Dose = Carbohydrates (g) / Insulin-to-Carb Ratio Total Dose = Correction Dose + Food Dose

If your current blood glucose is below target, the correction dose will be negative - this means you need less insulin than your food dose alone would require, because your blood sugar is trending low.

The total dose should always be positive. A negative total (if BG is very low) means you may need to treat the low before eating, not take any insulin - always follow your healthcare provider's guidance in that situation.

This calculation does not account for active insulin on board (IOB) from recent doses. If you have taken insulin in the past 2-4 hours, reducing your dose to avoid stacking is critical. See the Insulin Stacking Risk Estimator.

! Critical Medical Disclaimer
Insulin dose calculation is a life-critical medical decision. This tool provides an educational estimate only. Incorrect insulin doses can cause severe hypoglycemia (dangerously low blood sugar), which can lead to loss of consciousness, seizures, or death. This calculator does not account for active insulin on board (IOB), recent illness, exercise, alcohol consumption, or individual variation. Never administer insulin based solely on this calculator's output without guidance from your healthcare provider, endocrinologist, or certified diabetes educator. If you are experiencing hypoglycemia, treat it immediately - do not take insulin.