Carb Counter Calculator
Calculate total carbs, fiber, and net carbs for common foods by serving size in grams or cups.
Covers bread, rice, pasta, fruits, and vegetables.
Carbohydrate counting is the primary dietary management tool for people with Type 1 and Type 2 diabetes. It works by matching carbohydrate intake to insulin doses or medication, keeping blood glucose within a target range.
Key formulas:
Net Carbs = Total Carbohydrates − Dietary Fiber − Sugar Alcohols (÷2) Insulin-to-Carb Ratio (ICR): 1 unit of insulin covers X grams of carbs (set by your endocrinologist) Bolus Dose = Net Carbs ÷ ICR Blood Glucose Rise = Net Carbs × Glycemic Index Factor
What each variable means:
- Total Carbohydrates — from the nutrition label (grams per serving).
- Dietary Fiber — not digested; subtracted from total carbs because it does not raise blood glucose.
- Sugar Alcohols — partially absorbed; divide by 2 before subtracting (erythritol can be fully subtracted).
- ICR (Insulin-to-Carb Ratio) — determined by your doctor; a common starting ratio is 1 unit per 15 grams.
Worked example: A meal contains 52g total carbs, 6g fiber, 4g sugar alcohols (not erythritol).
Net Carbs = 52 − 6 − (4 ÷ 2) = 52 − 6 − 2 = 44g net carbs
With an ICR of 1:15: Bolus = 44 ÷ 15 = 2.9 units (round to 3 units per your doctor’s guidance)
Daily carb targets by goal (general guidelines — always follow your healthcare team’s advice):
- Very low carb / keto: 20–50g per day
- Moderate restriction: 100–130g per day
- ADA general guidance: 45–60g per meal
- Athletes with diabetes: 150–250g per day
Important: Never adjust insulin doses without consulting your endocrinologist or certified diabetes educator. This calculator is a learning and planning tool only.