Glycemic Load Calculator
Glycemic load (GL) is a more practical measure of how a food affects blood sugar than the glycemic index (GI) alone. While GI measures the speed of blood sugar rise from a standardised 50 g carbohydrate portion, GL adjusts for the actual grams of carbohydrate in a typical serving. A food can have a high GI but a low GL if you eat it in small portions, or vice versa. This calculator lets you enter a food's GI, its total carbohydrate content per serving, and its fibre content (to compute net carbs). The result is the glycemic load for that serving, classified as low (10 or less), medium (11-19), or high (20 or more), helping you make more informed dietary choices for blood sugar management.
Glycemic load formula
Net Carbs = Total Carbs - Fibre
GL = (GI x Net Carbs) / 100
GL categories: Low = 10 or below; Medium = 11 to 19; High = 20 or above.
Glycemic load: frequently asked questions
What is glycemic load (GL)?
Glycemic load combines a food's glycemic index (GI) with the actual amount of carbohydrates in a serving. It provides a more accurate picture of a food's effect on blood sugar than GI alone, because it accounts for portion size.
How is glycemic load calculated?
GL = (GI x Net Carbohydrates per serving in grams) / 100. For example, watermelon has a high GI of 72 but a low GL of about 4 per 120 g serving, because it contains few carbs by weight.
What are low, medium, and high glycemic load values?
A GL of 10 or less is low, 11-19 is medium, and 20 or more is high. A daily total GL of 100 or less is generally considered low. People with diabetes or insulin resistance benefit from choosing low-GL foods.
What is the difference between GI and GL?
GI measures how rapidly a carbohydrate food raises blood sugar on a scale of 0-100, based on a standard 50 g carbohydrate serving. GL adjusts for the actual grams of carbohydrate in a typical serving, giving a truer picture of glycaemic impact per eating occasion.
What are net carbohydrates?
Net carbohydrates are total carbohydrates minus dietary fibre. Fibre is not digested and does not raise blood sugar. For glycemic load calculation, use only the digestible (net) carbohydrate content: Net Carbs = Total Carbs - Fibre.
Official sources
- Harvard T.H. Chan School of Public Health: Glycemic Index and Glycemic Load.
- American Diabetes Association: Glycemic Index and Diabetes.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.