Health · Free tool
Insulin / Carb Ratio
Insulin-to-Carb Ratio (ICR): how many grams of carbs 1 unit covers. Insulin Sensitivity Factor (ISF / correction factor): how many mg/dL 1 unit drops your sugar. Both derived from your Total Daily Dose.
Sum of all insulin (basal + bolus) per day.
Always confirm with your endocrinologist before adjusting doses. Individual ratios vary by time-of-day, exercise, illness.
FAQ
Why does ICR change throughout the day?
Insulin sensitivity drops in the morning (dawn phenomenon — cortisol surge). Most type-1 diabetics need 1:8 in morning, 1:12 lunch, 1:15 evening. Adjust by meal.
Should I use 500 rule or 450 / 550?
500 is the most common starting point. Actual ratio comes from CGM data + carb logs over 1-2 weeks. Endocrinologists tweak from there.
Type 2 — does this apply to me?
Only if you're on intensive insulin therapy (basal + bolus). Most type-2 diabetics on metformin / SGLT2i don't need ICR — diet management is primary.