How Do You Calculate Insulin Dosage

Insulin Bolus Dosage Calculator

Use this calculator to estimate your mealtime and correction insulin bolus based on your current blood glucose, target blood glucose, carbohydrates consumed, and your personal insulin ratios.

e.g., 1 unit of insulin covers 15 grams of carbohydrates.

e.g., 1 unit of insulin lowers blood glucose by 50 mg/dL.

Calculated Insulin Bolus:

Correction Dose:

Carbohydrate Dose:

Total Bolus Insulin:

' + totalBolusInsulin.toFixed(1) + ' units

Always consult your healthcare provider before making any changes to your insulin regimen.

Understanding Insulin Dosage Calculation

Managing diabetes effectively often involves carefully calculating insulin doses, especially for individuals using multiple daily injections (MDI) or an insulin pump. This calculator helps estimate bolus insulin, which is taken with meals or to correct high blood sugar. It's crucial to understand the factors involved and always consult with your healthcare provider for personalized guidance.

What is Bolus Insulin?

Bolus insulin is short-acting or rapid-acting insulin taken to cover the carbohydrates consumed in a meal (mealtime bolus) or to bring down high blood glucose levels (correction bolus). It works quickly to manage blood sugar spikes.

Key Factors in Bolus Insulin Calculation:

1. Insulin-to-Carbohydrate Ratio (ICR)

Your Insulin-to-Carbohydrate Ratio (ICR) tells you how many grams of carbohydrates are covered by one unit of rapid-acting insulin. For example, an ICR of 1:15 means that 1 unit of insulin will cover 15 grams of carbohydrates. This ratio is highly individualized and determined by your doctor or diabetes educator based on your weight, activity level, insulin sensitivity, and other factors.

How it's used: To calculate the mealtime insulin dose, you divide the total grams of carbohydrates in your meal by your ICR.

Example: If you eat 60 grams of carbohydrates and your ICR is 1:15, you would need 60 / 15 = 4 units of insulin for the meal.

2. Insulin Sensitivity Factor (ISF) / Correction Factor

Your Insulin Sensitivity Factor (ISF), also known as the Correction Factor, indicates how much one unit of rapid-acting insulin will lower your blood glucose level. For instance, an ISF of 1:50 mg/dL means that 1 unit of insulin will lower your blood glucose by 50 mg/dL. Like the ICR, your ISF is unique to you and can change over time.

How it's used: To calculate the correction dose, you subtract your target blood glucose from your current blood glucose and then divide the difference by your ISF.

Example: If your current blood glucose is 180 mg/dL, your target is 100 mg/dL, and your ISF is 1:50, you would need (180 – 100) / 50 = 80 / 50 = 1.6 units of insulin for correction.

Note: If your blood glucose is already at or below your target, no correction dose is typically needed.

3. Current and Target Blood Glucose Levels

These values are essential for determining if a correction dose is needed and how much. Current blood glucose is measured before a meal or when a correction is required. Target blood glucose is the ideal blood sugar level you aim for, usually set by your healthcare provider.

Blood glucose levels are commonly measured in milligrams per deciliter (mg/dL) in the United States and some other countries, or in millimoles per liter (mmol/L) in many other parts of the world. If your readings are in mmol/L, you can convert them to mg/dL by multiplying by 18 (e.g., 7 mmol/L * 18 = 126 mg/dL).

How to Use the Calculator:

1. Enter Current Blood Glucose: Input your current blood sugar reading (e.g., from a glucose meter).
2. Enter Target Blood Glucose: Input your desired blood sugar level before a meal or correction.
3. Enter Carbohydrates Consumed: Input the total grams of carbohydrates you plan to eat for your meal.
4. Enter Insulin-to-Carbohydrate Ratio (ICR): Input your personal ICR (e.g., 15 for 1:15).
5. Enter Insulin Sensitivity Factor (ISF): Input your personal ISF (e.g., 50 for 1:50 mg/dL).
6. Click "Calculate Insulin Bolus": The calculator will provide your estimated correction dose, carbohydrate dose, and total bolus insulin.

Important Disclaimer:

This calculator is for informational and educational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Insulin dosages are highly individual and must be determined and adjusted by a qualified healthcare professional, such as an endocrinologist or diabetes educator. Factors like exercise, stress, illness, and other medications can significantly impact insulin needs. Always follow your doctor's specific instructions and never adjust your insulin dose without their guidance.