Glycemic Load Calculator
Glycemic index tells you how fast. Glycemic load tells you how much it matters.
Your portion
How this is calculated
The formula: glycemic load = (GI × available carbohydrate in grams) ÷ 100, where available carbohydrate is total carbohydrate minus fiber.
Bands: per serving, 10 or under is low, 11–19 is medium, 20 or above is high. Across a full day, under 100 is low and over 120 is high.
Worked example: one cup of cooked lentils has a GI of 32 with 39.9 g total carbohydrate and 15.6 g fiber. Available carbohydrate is 24.3 g, so the load is (32 × 24.3) ÷ 100 = 7.8 — low.
The counter-example: watermelon has a high GI of 76, which sounds alarming, but a cup carries only 10.9 g of available carbohydrate. Its load is 8.3 — also low. This is exactly why glycemic index alone misleads.
Sources: GI values from the Foster-Powell, Holt and Brand-Miller international tables of glycemic index and glycemic load; carbohydrate and fiber from USDA FoodData Central.
Frequently asked
How do you calculate glycemic load?+
Glycemic load = (glycemic index × available carbohydrate in grams) ÷ 100. Available carbohydrate is total carbohydrate minus fiber, for the portion you actually eat.
What is a good glycemic load?+
Per serving: 10 or under is low, 11 to 19 is medium, and 20 or above is high. Across a whole day, under 100 is generally considered low and over 120 high.
What is the difference between glycemic index and glycemic load?+
Glycemic index rates how fast a fixed 50 g of carbohydrate from a food raises blood glucose. Glycemic load adjusts that for how much carbohydrate is actually in your portion. Watermelon has a high GI of 76 but only 11 g of available carbohydrate per cup, so its glycemic load is about 8 — low.
Do beans and lentils have a low glycemic load?+
Yes. Legumes combine a low glycemic index (28 to 32) with heavy fiber, so a full cup of lentils lands near 8 — low, despite nearly 40 g of total carbohydrate. This is the main reason legumes appear throughout blood-glucose research.
Does cooking change glycemic load?+
It does. Longer cooking gelatinises starch and raises the glycemic index — al dente pasta ranks well below overcooked pasta. Cooling cooked potatoes, rice, or pasta forms resistant starch, which lowers the effective load on reheating.
Related tools & articles
References
- Atkinson FS, Brand-Miller JC, Foster-Powell K, et al. International tables of glycemic index and glycemic load values 2021. Am J Clin Nutr. 2021;114(5):1625–1632.
- U.S. Department of Agriculture, Agricultural Research Service. FoodData Central. USDA, 2024.
Educational estimates only, not medical advice. Individual needs vary — consult a physician or registered dietitian.