Diabetes Insulin Dose Calculator

How to calculate an insulin dose?

Your total insulin dose is typically a combination of two parts: a correction dose to bring high blood sugar down to your target range and a meal dose to cover the carbohydrates you are about to eat.

Correction = (BG - Target) / ISF    |    Meal = Carbs / ICR

Using the calculator: an example

Imagine your current blood glucose (BG) is 200 mg/dL, your Target is 100 mg/dL, and your Insulin Sensitivity Factor (ISF) is 50. For your meal, you plan to eat 60g of carbs with an Insulin-to-Carb Ratio (ICR) of 1:15.

Step-by-step calculation:

1. Calculate correction: (200 - 100) / 50 = 2 units
2. Calculate meal dose: 60 / 15 = 4 units
3. Sum for total: 2 + 4 = 6 units

Frequently Asked Questions

When should I take my insulin?

Most rapid-acting insulins should be taken 15-20 minutes before eating (pre-bolusing). This allows the insulin to start working just as the glucose from your food enters your bloodstream.

What if my blood sugar is low?

If your blood sugar is below 70 mg/dL, follow the 15-15 rule: eat 15 grams of fast-acting carbs, wait 15 minutes, and re-check. Do not take meal insulin until your blood sugar is back in a safe range.

Is this medical advice?

Important: This tool is for educational purposes only. You must consult your doctor or endocrinologist to determine your specific insulin sensitivity and carb ratios before making any medical decisions.