Glycemic Load Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/6/2026
Glycemic load is calculated with GL = (glycemic index × carbohydrates in grams) ÷ 100. A serving of corn flakes (GI 82, 25 g of carbs) has a glycemic load of 20.5, considered high.
Explanation
The glycemic index (GI) measures how quickly a food raises blood sugar, but only for a fixed amount of carbohydrates (often 50 g), without accounting for the amount actually eaten in a typical serving. Glycemic load corrects this limitation by combining both the food's GI and the amount of carbohydrates actually present in the portion consumed, making it a more representative indicator of a meal's real impact on blood sugar. A food with a high GI but eaten in a small amount (watermelon, for example, high GI but few carbs per serving) can therefore have a low glycemic load, while a food with a moderate GI eaten in a large amount can have a high load. Commonly used thresholds classify a glycemic load of 10 or less as low, 11 to 19 as moderate, and 20 or more as high.
Example: a serving of corn flakes
Inputs
Glycemic index: 82. Carbohydrates in the serving: 25 g.
Calculation
Glycemic load = (82 × 25) ÷ 100 = 2,050 ÷ 100 = 20.5.
Result
This serving has a glycemic load of 20.5, classified as high (threshold starts at 20).
Frequently asked questions
Why is glycemic load a better indicator than the glycemic index alone?
Because the glycemic index says nothing about the amount of carbohydrates actually consumed: it compares foods at an equal amount of carbohydrates (often 50 g), which doesn't always match a realistic serving. Glycemic load factors in the actual amount, making it more representative of a meal's real impact on blood sugar.
Where can I find the glycemic index of a specific food?
Public nutrition databases and glycemic index tables published by research institutes list the GI of many common foods. The value can vary by variety, ripeness, cooking method, and the presence of other nutrients in the same meal (fiber, protein, fat), which generally slow down carbohydrate absorption.
Does a high glycemic load mean a food should be avoided?
Not necessarily in isolation: the glycemic load of a whole meal depends on the combination of foods eaten together, not a single ingredient taken separately. Needs and tolerances also vary between individuals, particularly with diabetes or insulin resistance — a healthcare professional remains the reference for personalized recommendations.