What formula does this calculator use?

For Type 1, TDD = 0.4–0.5 units per kg of body weight. For Type 2 (insulin-naive), TDD = 0.5–0.6 u/kg is a common starting point. The calculator uses the midpoint of each range and rounds to the nearest whole unit.

What is the basal/bolus split?

The standard starting split is 50% of TDD as long-acting basal insulin and 50% as rapid-acting bolus insulin divided equally across three meals (~17% each meal). Some clinicians use a 40/60 or 60/40 split — adjust per your provider.

What is the insulin sensitivity factor (ISF)?

ISF (also called the correction factor) estimates how many mg/dL one unit of insulin lowers blood glucose. The "1700 Rule" for rapid-acting insulin is: ISF = 1700 ÷ TDD. Some protocols use 1500 for regular insulin.

Is this a substitute for medical advice?

No. This tool provides educational estimates based on published weight-based guidelines. Always consult your endocrinologist or diabetes care team before changing your insulin regimen.

Why does my actual dose differ?

Weight-based formulas are starting-point estimates. Actual doses vary with carbohydrate intake, activity level, insulin resistance, concurrent medications, renal function, and individual response.

What is the insulin-to-carb ratio (ICR)?

ICR = 500 ÷ TDD (the "500 Rule"). It tells you how many grams of carbohydrate one unit of rapid-acting insulin covers. For example, TDD = 40 → ICR = 1:12.5 (one unit per 12.5 g carbs).

Total Daily Insulin Calculator

Name: Total Daily Insulin Calculator
Availability: InStock
Author: Nham Vu

Enter your weight and diabetes type to estimate total daily insulin and see the recommended basal/bolus split.

Patient Details

Body Weight

Diabetes Type

Type 1 Type 2

Insulin Regimen

Rapid-acting bolus Regular insulin

Enter your weight and click Calculate to see your insulin estimates.

Summary