Glycemic Load CalculatorFree online fitness & health calculator — instant results, no sign-up
Calculate glycemic load from glycemic index and available carbohydrate.
For general information only. This is not medical advice, diagnosis, dosing guidance or a treatment recommendation. Talk to a doctor or other qualified health professional about your health, pregnancy, or diet.
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About the Glycemic Load Calculator
The Glycemic Load Calculator estimates glycemic load from a food’s glycemic index and the grams of available carbohydrate in the portion you eat. It combines carbohydrate quality and quantity rather than relying on glycemic index alone. With a glycemic index of 55 and 30 g of available carbohydrate, the estimated glycemic load is 16.5.
- Glycemic index
- The food’s glycemic index (GI) is a unitless measure of its blood-glucose effect relative to glucose, which has a reference value of 100.
- Available carbohydrate (g)
- Available carbohydrate is the amount of digestible carbohydrate in your selected portion, entered in grams and excluding dietary fiber.
Formula and method
GL = (GI × C) / 100; with the default inputs: GL = (55 × 30) / 100 = 16.5.
- GLEstimated glycemic load of the selected portion, reported without units.
- GIGlycemic index of the food on the glucose-reference scale.
- CAvailable carbohydrate in the selected portion, in grams.
The calculator multiplies the entered glycemic index by the grams of available carbohydrate, then divides the product by 100. It reports the resulting glycemic load together with a reminder that the estimate does not predict an individual’s exact glucose response.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Glycemic index55
- Available carbohydrate30 g
Results
- Glycemic load16.5
- NoteApproximation; individual results vary.
How to use the Glycemic Load Calculator
- 1Find a glycemic index value for the food, preferably one matching its variety and preparation and using glucose as the reference.
- 2Enter that value in Glycemic index; the default is 55.
- 3Determine the available carbohydrate in the portion you plan to eat and enter it in Available carbohydrate (g); the default is 30.
- 4Calculate the result: the default inputs give (55 × 30) / 100 = 16.5.
- 5Read the glycemic load alongside the approximation note, keeping portion size and individual variation in mind.
Reading your result
The “Glycemic load” row shows the estimated carbohydrate-related glycemic impact of the entered portion. The default result is 16.5, which falls in the commonly used medium range: low is 10 or less, medium is greater than 10 and less than 20, and high is 20 or more. The “Note” row states “Approximation; individual results vary.” This means the value is an estimate, not a predicted blood-glucose reading or a measure of overall nutritional quality.
Limitations
The calculation assumes that the GI value represents the food you eat and that available carbohydrate matches your actual portion. GI varies with variety, ripeness, processing, cooking, and testing conditions. Fat, protein, fiber, other foods in a meal, activity, medications, and individual physiology can change glucose responses. Nutrition-label definitions differ by country, and sugar alcohols complicate estimates of available carbohydrate. Glycemic load is not a blood-glucose concentration and should not be used to set medication or insulin doses.
Common questions
How is glycemic load different from glycemic index?+
Glycemic index describes a food’s relative glucose effect for a standardized amount of available carbohydrate. Glycemic load also accounts for the carbohydrate amount in your portion, so a GI of 55 with 30 g of available carbohydrate produces a GL of 16.5.
Should I enter total carbohydrate or available carbohydrate for glycemic load?+
Enter available carbohydrate. On labels where total carbohydrate includes fiber, subtracting dietary fiber is a common starting point. If the label already excludes fiber from carbohydrate, do not subtract it again; foods containing sugar alcohols may require more specific information.
What happens to glycemic load if I change the portion?+
For the same food and GI, glycemic load changes in direct proportion to available carbohydrate. Update the carbohydrate grams to match the portion you actually eat rather than changing GI to reflect portion size.
Can I use one glycemic index value for an entire mixed meal?+
Only if you have an appropriate GI estimate for that meal. Alternatively, calculate each carbohydrate-containing food’s glycemic load and add the results for a rough meal estimate, recognizing that interactions among foods can alter the actual glucose response.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
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Results are estimates for informational purposes and are not financial, medical or legal advice.