17/09/2026
💉 HOW TO CALCULATE INSULIN REQUIREMENT — A SIMPLE STEPWISE GUIDE 🩺🧠
📌 Insulin therapy should always be individualized according to the patient’s type of diabetes, body weight, glycaemic status, insulin sensitivity, renal function, and risk of hypoglycaemia.
💡 Easy Formula:
Body Weight (kg) × Total Daily Dose (TDD) = Total Daily Insulin Requirement
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1️⃣ STEP 1: CALCULATE THE TOTAL DAILY DOSE (TDD)
🔵 TYPE 1 DIABETES MELLITUS
▪️ Typical starting dose: 0.4–0.6 units/kg/day
▪️ Newly diagnosed / honeymoon phase: ~0.4 units/kg/day
▪️ Most adults: ~0.5 units/kg/day
▪️ Insulin-resistant patients may require 0.7–1.0 units/kg/day
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🟢 TYPE 2 DIABETES MELLITUS
Basal insulin initiation:
▪️ 10 units once daily
OR
▪️ 0.1–0.2 units/kg/day
If a basal–bolus regimen is required:
▪️ Start with 0.3–0.5 units/kg/day
▪️ Some insulin-resistant patients may ultimately require 0.5–1.0 units/kg/day
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🟣 PREGNANCY — GENERAL GUIDE
▪️ 1st trimester: ~0.7 units/kg/day
▪️ 2nd trimester: ~0.8 units/kg/day
▪️ 3rd trimester: ~0.9–1.0 units/kg/day
⚠️ Insulin requirements increase during pregnancy and should be individualized using SMBG/CGM and clinical monitoring.
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2️⃣ STEP 2: DIVIDE THE TOTAL DAILY DOSE
🔷 BASAL–BOLUS REGIMEN
40–50% → BASAL INSULIN
▪️ Long-acting insulin
(e.g., glargine, degludec, detemir)
⬇️
50–60% → RAPID-ACTING (BOLUS) INSULIN
▪️ Divide initially before breakfast, lunch and dinner
▪️ Adjust according to glucose readings and meal patterns.
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🧮 EXAMPLE 1 — TYPE 1 DIABETES
Patient weight = 60 kg
TDD = 60 × 0.5 = 30 units/day
➡️ Basal insulin ≈ 15 units
➡️ Bolus insulin ≈ 15 units
Divide bolus:
🍳 Breakfast = 5 units
🍛 Lunch = 5 units
🍽️ Dinner = 5 units
Initial regimen:
▪️ Basal insulin 15 units at bedtime
▪️ Rapid-acting insulin 5 units before each main meal
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🧮 EXAMPLE 2 — TYPE 2 DIABETES
Patient weight = 80 kg
Starting basal insulin:
0.2 × 80 = 16 units once daily
OR
Start with 10 units once daily and titrate according to fasting blood glucose.
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3️⃣ STEP 3: TITRATE THE DOSE
🟦 BASAL INSULIN
✅ Increase by 2 units every 3 days
(or every 3–7 days) until fasting glucose reaches the individualized target.
🟪 IF HYPOGLYCAEMIA OCCURS
⚠️ Consider reducing the insulin dose by 10–20% or more when clinically indicated.
💡 Clinical Pearl:
If pre-lunch glucose is consistently high, adjust the breakfast bolus insulin rather than automatically increasing basal insulin.
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🎯 GLYCAEMIC TARGETS — MOST NON-PREGNANT ADULTS
🕐 Fasting glucose:
80–130 mg/dL
(4.4–7.2 mmol/L)
🍽️ 1–2 hour post-meal glucose:
