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METABOLICFreeLast updated: 2026

Insulin: Pharmacology, Types & Correction Dose Calculator

Educational Insulin Calculator

Educational · No prescription

TDD, ICR, ISF, Correction Dose and meal bolus — validated formulas (Walsh & Roberts) on a single screen.

1. Patient data

Diabetes type
Insulin type
Glucose unit

2. Calculate dose for a meal

3. Calculated parameters

Total Daily Dose (TDD)
35.0U/day

units/day — base for all calculations below

Basal (50% of TDD)
17.5U

fasting coverage (NPH 2× daily or glargine/degludec 1×)

Daily bolus (50% of TDD)
17.5U

split across 3 main meals (~⅓ each)

Insulin-to-Carb Ratio (ICR)
1:14g of CHO per 1 U

how many grams of carb 1 unit covers · 500 ÷ 35.0

Insulin Sensitivity Factor (ISF)
51mg/dL per 1 U

how much BG drops per 1 correction unit · 1800 ÷ 35.0

4. Recommended dose (educational)

Meal bolus
4.2U

covers meal carbohydrates · 60g ÷ 14

Correction dose
2.1U

lowers BG to target · (220−110) ÷ 51

Total bolus
6.3U

sum of both — single dose before the meal

How do these formulas work?

500 rule (rapid) / 450 rule (regular)

Walsh & Roberts (Pumping Insulin, 6th ed., 2017) describe that dividing 500 by TDD approximates how many grams of carbohydrate 1 unit of rapid analogue covers. For regular human insulin, use 450 — longer duration reduces apparent sensitivity. Very sensitive patients trend toward high ICR; resistant, low ICR.

1800 rule (rapid) / 1500 rule (regular)

The 1800 rule estimates how many mg/dL 1 unit of rapid analogue lowers blood glucose. For regular: 1500. In mmol/L, divide 100 (rapid) or 83 (regular) by TDD. Empirical origin: insulin pump data from the 1990s organized by Davidson and Walsh.

Insulin on Board (IOB)

The literature describes effective action of rapid analogues for 4–5h (regular: 6–8h). Overlapping doses in a short window can stack IOB and cause hypoglycemia. Pumps calculate linear IOB: IOB ≈ Dose × (1 − time/duration). Professional assessment individualizes this calculation.

Essential notice

This tool is strictly educational, based on formulas described by Walsh & Roberts (Pumping Insulin), American Diabetes Association (Standards of Care) and primary literature. Values are literature starting points — they do NOT constitute medical prescription, diagnosis or individual therapeutic guidance. Dose adjustments, insulin type selection, glycemic targets and hypoglycemia management require evaluation by an endocrinologist or treating physician, considering renal function, age, pregnancy, physical activity, concomitant medications and patient monitoring patterns.

Source: Walsh J, Roberts R. Pumping Insulin, 6th ed. Torrey Pines Press, 2017. ADA Standards of Medical Care in Diabetes (annual update).

⚠️ The information on this page is based on scientific publications and is for educational purposes only. It does not constitute medical prescription, diagnosis, therapeutic guidance, or recommendation for use. Any clinical intervention must be individualized by a qualified healthcare professional.

Complete scientific analysis of insulin: pharmacology of rapid analogues (lispro, aspart, glulisine), regular, NPH and basal (glargine, detemir, degludec), rule of 500/450 (ICR), 1800/1500 (ISF) and free educational Correction Dose, ICR, ISF and meal bolus calculator.

Mechanism of Action

O Insulin atua através de mecanismo descrito na literatura científica. Conteúdo completo em breve.

Applications Described in Literature

1

Aplicação 1

Descrito na literatura científica

2

Aplicação 2

Descrito na literatura científica

3

Aplicação 3

Descrito na literatura científica

Relevant Studies

Estudos em andamento — conteúdo em breve

PubMed · n/d

FAQ

What is an insulin Correction Dose (Correction Bolus)?

The Correction Dose is the amount of rapid insulin calculated to lower blood glucose to a therapeutic target, without covering food. The formula described in the literature is CD = (Current BG − Target BG) ÷ Insulin Sensitivity Factor (ISF). It is educational — individualization requires professional assessment.

How are ICR and ISF calculated in the Walsh & Roberts rule?

Walsh & Roberts (Pumping Insulin, 6th ed.) describe: ICR (g of carb per 1U) = 500 ÷ TDD for rapid analogues (450 ÷ TDD for regular); ISF (mg/dL per 1U) = 1800 ÷ TDD for rapid (1500 ÷ TDD for regular; 100 ÷ TDD in mmol/L). TDD = Total Daily Dose. These are literature starting points, not prescriptions.

What is the difference between rapid insulin (lispro/aspart) and regular?

Rapid analogues (lispro, aspart, glulisine) start acting in 5-15 min, peak 30-90 min and last 3-5h. Regular human insulin starts in 30-60 min, peaks 2-4h and lasts 5-8h. That's why the 1500 rule (regular) vs 1800 rule (rapid) — regular's longer duration reduces apparent sensitivity per unit.