Definition

Glycemic load (GL) estimates the total carbohydrate impact of a food based on both its glycemic index and the amount of available carbohydrate in a real serving. It answers the question GI cannot: “for the amount I actually eat, how much glucose response can I expect?”

The Formula

GL = GI × available carbohydrate per serving ÷ 100

Where available carbohydrate is the carbohydrate minus fiber:

available carbohydrate = total carbohydrate − fiber

Worked Example (Apple)

A medium apple (182 g) has about 25 g of carbohydrate and 4.4 g of fiber. With a published GI of 36:

available carbohydrate = 25.1 − 4.4 = 20.7 g
GL = 36 × 20.7 ÷ 100 ≈ 7.4

A GL of 7 is low impact — which matches why whole apples are generally well tolerated. Compare that with a cup of cooked white rice (GI ~73, about 44 g available carbohydrate):

GL = 73 × 44 ÷ 100 ≈ 32

A GL of 32 is high impact — the same “one serving” of rice produces a far larger expected response.

The Standard Ranges

Why GL Matters More Than GI in Practice

GL combines how fast (GI) with how much (carbohydrate amount). Watermelon is the classic example: high GI (~76) but mostly water, so a normal portion has a moderate GL. GI alone would mislead you.

In short: GL estimates the blood sugar impact of a realistic serving. Use it together with GI — and remember every GL here is an estimate, not a prediction of your personal response. See GI vs GL and the methodology for how DMSafeHaven calculates it.