How to use the insulin to carbohydrate ratio calculator
Estimate how many grams of carbohydrate one unit of insulin covers, using the 500 rule. Enter total daily insulin dose in the field above; the carbohydrates covered per unit, insulin needed for 15 g of carbohydrate are computed instantly and plotted on the chart so you can see how the answer changes.
Common searches this calculator answers include “500 rule insulin carb ratio”, “carb ratio insulin”, “grams of carbs per unit”, “calculate insulin to carbohydrate ratio”, “find carbohydrates covered per unit”.
Formula
Variables
- tdd — Total daily insulin dose (units)
Worked example
With total daily insulin dose = 40 units, the calculator gives carbohydrates covered per unit ≈ 12.5 g; insulin needed for 15 g of carbohydrate ≈ 1.2 units.
Frequently asked questions
What is the insulin to carbohydrate ratio calculator used for?
Estimate how many grams of carbohydrate one unit of insulin covers, using the 500 rule. It helps with questions such as “500 rule insulin carb ratio”, “carb ratio insulin”, “grams of carbs per unit”.
What is the formula for the insulin to carbohydrate ratio calculation?
Carbohydrates covered per unit (g) = 500 / tdd. Insulin needed for 15 g of carbohydrate (units) = 15 / [Carbohydrates covered per unit]. Here tdd is total daily insulin dose (units).
What inputs do I need for the insulin to carbohydrate ratio (500 rule) calculator?
You need total daily insulin dose in units. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use the insulin to carbohydrate ratio calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the insulin to carbohydrate ratio result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.