💉 Insulin Dosage Calculator
Generate a starting basal-bolus insulin plan using evidence-based weight formulas, carbohydrate ratio, and correction factor.
Use actual body weight unless instructed to use adjusted body weight.
Use your care team’s recommended target. Typical ADA target range for many adults is 80-130 mg/dL fasting/pre-meal.
- Total daily dose (TDD)
- 50:50 basal/bolus split
- Carbohydrate ratio (500 rule)
- Correction factor / insulin sensitivity (1800 rule)
Based on ADA/EASD recommendations for starting intensive insulin therapy. Confirm with an endocrinologist.
How to Use This Calculator
Enter accurate weight
Type your current body weight in kilograms. For patients with obesity, some clinicians use adjusted body weight—follow your care team’s guidance.
Select a dosing scenario
Choose the clinical situation that best matches the patient (new onset, active, type 2, insulin resistant) or provide a custom factor specified by a clinician.
Calculate and personalise
Click “Calculate Insulin Plan.” Review TDD, basal/bolus split, carbohydrate ratio, and correction factor. Individualise based on glucose logs, hypoglycaemia risk, renal function, and clinical protocols.
Formula
Weight-based insulin initiation is endorsed by ADA/EASD consensus for basal-bolus therapy. Common starting points include 0.3-0.6 units/kg/day, titrated to fasting and pre-meal targets. This calculator applies:
- Total Daily Dose (TDD) = Body weight (kg) × selected factor (units/kg)
- Basal insulin ≈ 50% of TDD; rapid-acting bolus insulin ≈ 50% of TDD divided over meals
- Carbohydrate ratio (grams per 1 unit) = 500 ÷ TDD (rapid-acting analogues)
- Correction factor (mg/dL per 1 unit) = 1800 ÷ TDD (rapid-acting analogues)
Alternative rules (e.g., 450 or 1700) apply for regular insulin or specific populations. Basal insulin adjustments of 1-2 units every 3 days, or 10-15% weekly, are typical until fasting targets are met.
Full Description
Basal-bolus therapy mimics physiologic insulin secretion by combining long-acting basal insulin with rapid-acting mealtime doses. Weight-based formulas provide a safe starting framework before individual titration based on glucose patterns.
Carb counting and correction dosing give patients flexibility. The 500 rule estimates how many grams of carbohydrate one unit of rapid insulin covers, while the 1800 rule predicts how far a single unit will drop glucose. These rules are starting points that should be tuned using continuous glucose monitoring, fingerstick data, and dietitian coaching.
Factors such as renal impairment, steroid therapy, pregnancy, or high-intensity exercise can change insulin requirements. Use the calculator as a discussion tool during diabetes education, reinforcing the need for professional oversight and hypoglycaemia prevention strategies.
Frequently Asked Questions
Is the 50:50 basal-bolus split always correct?
No. Some individuals need more basal (60%) or more bolus (40%) based on daytime activity, gastroparesis, or pump settings. Use the split as a starting reference.
Can I use pounds instead of kilograms?
Convert pounds to kilograms by dividing by 2.2046 before using the calculator.
What about basal-only therapy?
Basal-only dosing often starts at 0.1-0.2 units/kg/day. This calculator targets full basal-bolus therapy; consult simplified protocols for basal-only adjustments.
Do the 500 and 1800 rules work for children?
Paediatric dosing varies widely. Clinicians may use 300-500 for carb ratios and 1500-2000 for correction factors depending on age and puberty status. Always follow paediatric endocrinology guidance.
How do I adjust for exercise?
Exercise increases insulin sensitivity. Your diabetes educator can help plan pre-exercise carb intake, basal adjustments, or temporary pump targets to reduce hypoglycaemia risk.