If you use rapid-acting insulin at meals, your diabetes care team may have given you an insulin-to-carb ratio (ICR). It tells you how many grams of carbohydrate one unit of insulin covers. A ratio of 1:10 means one unit for every 10 g of carbs, so a 60 g meal would call for 6 units.
Many people also have a correction factor (sometimes called insulin sensitivity factor). It describes how much one unit is expected to lower your glucose — for example 40 mg/dL or 2.2 mmol/L per unit. If you are above your target before a meal, the correction dose is (current glucose − target) ÷ correction factor, and it is added to the carb dose. If you are below target the result is negative and reduces the dose.
This page simply does that arithmetic so you can double-check your own maths. It does not account for insulin still active from an earlier dose, planned exercise, illness, alcohol, or the many other things that affect dosing — and your ratios may differ by time of day. Treat the result as an estimate aid only, and never use a ratio or correction factor that was not set for you by your clinician.
Estimate aid only. This calculator does simple arithmetic with the numbers you enter. It does not know about insulin already on board, exercise, illness or your full treatment plan. Only use ratios and correction factors given to you by your diabetes care team, and confirm every dose with them or with your own dosing instructions.
Estimated bolus
- Carb dose: 60 g ÷ 10 g/unit
- 6.00 u
- Suggested total (estimate)
- 6.00 u
- Rounded to nearest 0.5 unit
- 6.0 u
Formula: (carbs ÷ ratio) + ((current − target) ÷ correction factor). Does not account for insulin on board. Not a dosing recommendation.
Medical Disclaimer: This content is informational only and is not medical advice. Always consult your doctor or a qualified healthcare professional before making changes to your diabetes management plan. If you think you are having a medical emergency, call 911.
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