Weight-Based Insulin Dosing Calculator

Adjustable weight-based insulin dose calculator. Set your own dose factor and see TDD, basal/bolus split, carb ratio, and sensitivity factor — with a full comparison table. Educational use only.

Educational use only. Results are estimates using published formulas. Not medical advice. Never change your insulin dose without consulting your doctor or diabetes care team.

🏋️ Weight-Based Dosing Calculator

ADA standard: 0.4–0.6 u/kg. Type 2 naïve start: 0.1–0.2 u/kg.

Results for Your Factor

units / day TDD
Basal (~50%)
units/day
Bolus pool (~50%)
units/day
Carb ratio
g per unit
ISF
mg/dL per unit
Calculation shown:
Comparison — Common Dose Factors
FactorLabelTDDBasalICR (g/u)ISF (mg/dL/u)

How to Use This Calculator

Enter Your Weight

Input weight in kg or lbs. The calculator converts automatically on toggle.

Set the Dose Factor

The ADA recommends 0.4–0.6 for most adults. Use 0.1–0.2 for conservative Type 2 starts. Increase to explore higher-resistance scenarios.

Choose Insulin Type

Rapid-acting analogs use the 1800 Rule for ISF. Regular insulin uses 1500.

Review Results

See TDD, basal, bolus pool, ICR, and ISF for your chosen factor.

Compare Across Factors

The comparison table shows key values at 0.2, 0.4, 0.5, and 0.6 u/kg so you can see how the dose factor changes each output.

Discuss With Your Team

Use these numbers as a conversation starter — not a self-prescribed regimen. Your provider determines the right factor for you.

Understanding Weight-Based Insulin Dosing

Weight-based insulin dosing is the clinical foundation for estimating starting total daily dose (TDD). It scales insulin need to body mass — larger bodies typically require more insulin. The dose factor (units per kg per day) is chosen based on the patient's diabetes type, insulin sensitivity, and clinical context.

The Core Formula

TDD (units/day) = Weight (kg) × Dose Factor (u/kg/day)

All derived values — basal, bolus pool, ICR, ISF — follow directly from TDD. This makes the dose factor the single most important variable in the calculation. Source: ADA Standards of Care 2024, Section 9; AACE Algorithm 2020.

Choosing the Right Dose Factor

FactorClinical Context
0.1–0.2 u/kgType 2 insulin-naïve conservative start; elderly with high hypo risk
0.4 u/kgType 1, insulin-sensitive (lean, very active)
0.5 u/kgType 1 standard midpoint (ADA default)
0.6 u/kgType 1, higher resistance or less active
>0.6 u/kgSignificant insulin resistance; guided by clinical titration

The dose factor is a starting point. After initiation, the actual TDD is refined through titration — increasing or decreasing based on blood glucose patterns, hypoglycemia events, and lifestyle factors. The formula gives you the right ballpark; monitoring gets you to the right number.

Sources & References

  1. American Diabetes Association. Standards of Medical Care in Diabetes — 2024. Link
  2. AACE/ACE. Comprehensive Type 2 Diabetes Management Algorithm 2020. Link
  3. Walsh J, Roberts R, Bailey T. "Guidelines for Optimal Bolus Calculator Settings." J Diabetes Sci Technol. 2011;5(1):129–135.

Last reviewed: June 2025

Frequently Asked Questions

Weight-based insulin dosing estimates total daily dose by multiplying body weight in kilograms by a clinical dose factor. The ADA recommends 0.4–0.6 u/kg/day as the starting range for most adults. The formula is TDD = weight (kg) × factor. This serves as a starting point — actual requirements are refined through weeks of blood glucose monitoring and dose adjustment with a healthcare provider.

For most adults with Type 1, 0.5 u/kg is the standard midpoint (ADA). Lean, very active people may use 0.4 u/kg; those with higher insulin resistance may use 0.6. Insulin-naïve Type 2 patients typically start at 0.1–0.2 u/kg to minimise hypoglycemia risk. The right factor for any individual is determined through clinical assessment and titration — not by formula alone. Use this tool for educational understanding, then discuss with your provider.

Weight-based formulas are clinically validated starting points, not precision prescriptions. They work well for initiating therapy and give the right order of magnitude for most adults. However, individual variation in insulin sensitivity is substantial — two people of identical weight may need very different doses. Real accuracy requires titration: adjusting based on actual blood glucose patterns, hypoglycemia events, and lifestyle factors over days and weeks.

Yes, often significantly. Weight loss — especially from dietary changes, GLP-1 receptor agonists (like semaglutide), or bariatric surgery — typically reduces insulin requirements as insulin sensitivity improves. In some Type 2 cases, substantial weight loss can allow discontinuation of insulin entirely. Conversely, weight gain usually increases insulin needs. If your weight changes by more than ~5–10 kg, discuss recalculating your doses with your provider.

This calculator allows a fully adjustable dose factor (0.1–1.5 u/kg/day) and generates a comparison table across multiple dose factors, making it useful for educational exploration of different dosing strategies. The dose-by-weight calculator focuses on the standard 0.4–0.6 range with a simpler preset-dropdown interface. Both use the same underlying formula.

This calculator is for educational purposes only. Not medical advice. Never change your insulin dose without consulting your doctor or diabetes care team.