Glycemic Index Meal Calculator

About this calculator

The glycemic index (GI) ranks individual carbohydrate-containing foods from 0 to 100 by how quickly they raise blood glucose relative to pure glucose, a scale developed by Dr. David Jenkins at the University of Toronto in 1981. A single food's GI, however, says nothing about a real plate of food that mixes several ingredients, so this calculator computes a carb-weighted average GI across every item in a meal — each food's GI is weighted by the share of total carbohydrate grams it contributes — and then derives the meal's glycemic load (GL), which factors in portion size (GL = GI × carbs in grams ÷ 100).

Dietitians and diabetes educators use meal-level GI and GL to explain why pairing a high-GI food like white rice with fiber, protein, or fat tends to blunt the overall blood-sugar spike, and endurance athletes use similar logic in reverse — favoring higher-GI carbs right before or during exercise for fast glucose availability, and lower-GI carbs beforehand for sustained energy.

Enter each food's carbohydrate content and known GI value and this calculator returns the meal's weighted GI along with its glycemic load classification.