Insulin Starting Dose Calculator (Weight-Based Basal-Bolus)

How it works

Total daily dose (U) = weight (kg) × 0.3–0.6 U/kg · basal = 50% once daily · prandial = 50% ÷ 3 meals · insulin-to-carb ratio = 500 ÷ TDD (g per U) · correction factor = 1800 ÷ TDD (mg/dL per U) or 100 ÷ TDD (mmol/L per U)

For people starting a basal-bolus insulin regimen, guidelines estimate the total daily dose from body weight. In the RABBIT 2 trial (Umpierrez et al., Diabetes Care 2007) hospitalized patients with type 2 diabetes started on 0.4 U/kg/day if glucose was 140–200 mg/dL and 0.5 U/kg/day if 201–400 mg/dL, with 0.3 U/kg/day recommended for older adults and those with reduced kidney function; half is given as basal insulin and half as rapid-acting insulin split across meals. Adults with type 1 diabetes usually need 0.4–1.0 U/kg/day. The 500 and 1800 (or 100 in mmol/L) rules give starting carbohydrate ratios and correction factors that are then adjusted to glucose records.

Worked example

An 80 kg adult with glucose around 9 mmol/L (160 mg/dL) at 0.4 U/kg: total daily dose = 80 × 0.4 = 32 U/day, split into 16 U of basal insulin once daily and 5 U of rapid-acting insulin with each of three meals (16 ÷ 3). Starting ratios: 1 U per 16 g of carbohydrate (500 ÷ 32) and a correction factor of 3.1 mmol/L (56 mg/dL) per unit.

Sources: Umpierrez GE et al. Randomized study of basal-bolus insulin therapy in the inpatient management of patients with type 2 diabetes (RABBIT 2 trial). Diabetes Care 2007;30:2181–6 · American Diabetes Association. Standards of Care in Diabetes — Diabetes Care in the Hospital and Pharmacologic Approaches

Frequently asked questions