Carb Counting Basics for Diabetes
How people on mealtime insulin match doses to carbohydrate.
The idea
Carbohydrate raises blood sugar most, so people on mealtime insulin estimate grams of carbohydrate and use an insulin to carb ratio.
Correction doses
A correction factor estimates how far one unit lowers glucose. Both numbers are personal and set by the care team.
Tools
Food labels, measuring cups and apps help with counting. Always follow your clinician’s plan rather than general formulas.
Try it: Insulin-to-Carb Ratio Calculator
Example with sample values. Open the full calculator →
Carb ratio1 : 13 u/g
Correction factor45 mg/dL per unit
Meal + correction6.4 units
These rules of 500 and 1800 are general starting points only. Never change insulin doses without your diabetes care team.
Educational content only. This article does not replace advice from a qualified health professional. Medical disclaimer.