Home›Calculators›Health›Glycemic Index Calculator

Glycemic Index Calculator

Health

Look up the glycemic index of common foods and see whether it falls in the low, medium, or high GI category, plus an estimated glycemic load per serving.

Food

Glycemic index values are approximate, glucose-referenced averages — actual values vary by ripeness, cooking method, and how a food is combined with fat, protein, or fiber.

Glycemic Index

0

GI Category

—

Serving Carbs

0 g

Est. GL

0

What is a Glycemic Index?

A Glycemic Index Calculator looks up the glycemic index (GI) of common foods — a scale from 0 to 100 that ranks how quickly a food's carbohydrate raises blood glucose relative to pure glucose. Foods with a GI of 55 or below are classified as low GI, 56-69 as medium GI, and 70 or above as high GI, based on the widely referenced University of Sydney glycemic index research.

This calculator draws on published GI values and typical serving carbohydrate data to return not just the GI number but also an estimated glycemic load for a standard serving, connecting directly to the Glycemic Load Calculator for any custom food or portion. It's a useful reference alongside broader nutrition tools like the Carb Calculator and Net Carbs Calculator.

How to use this Glycemic Index calculator

  1. Open the Food dropdown and select the item you want to look up.
  2. Review the Glycemic Index value shown as the primary result.
  3. Check the GI Category badge to see whether the food is classified as low, medium, or high GI.
  4. Note the Typical Serving Carbs figure to understand the portion size the GI reflects.
  5. Use the Estimated Glycemic Load as a more practical gauge of the food's real-world blood sugar impact, and cross-check with the Glycemic Load Calculator for other serving sizes.

Formula & Methodology

Glycemic index values in this calculator are approximated from the University of Sydney glycemic index database and related published nutrition research, using glucose as the GI = 100 reference standard.

Estimated Glycemic Load = (GI × typical serving carbohydrate grams) ÷ 100

Worked example: for white rice, boiled, with a published GI of 73 and roughly 43 g of carbohydrate in a typical serving:
- Estimated glycemic load = (73 × 43) ÷ 100 = 31.4
- A GI of 73 falls in the High GI category (70 or above).

For a fuller definition, see our glossary entry on Glycemic Index.

Frequently Asked Questions

The glycemic index (GI) is a scale from 0 to 100 that ranks how quickly a carbohydrate-containing food raises blood glucose compared to pure glucose, which is assigned a GI of 100. Foods are grouped into low (55 or under), medium (56-69), and high (70 or above) GI categories.
This calculator includes a curated list of common foods across grains, starchy vegetables, fruits, legumes, dairy, and sweeteners, each with a published or widely referenced GI value and typical serving carbohydrate content. Selecting a food instantly returns its GI, category, and an estimated glycemic load for a typical serving.
GI depends on how quickly a food's carbohydrate is digested and absorbed, which is influenced by fiber content, processing, ripeness, and cooking method rather than sugar content alone. For example, watermelon has a high GI despite low sugar density, while lentils have a low GI despite being carbohydrate-rich, due to their fiber and protein content.
Glycemic index measures how fast a food raises blood sugar per gram of carbohydrate, while glycemic load factors in the actual amount of carbohydrate in a typical serving, giving a more practical picture of real-world impact. A food can have a high GI but a low glycemic load if a typical serving contains very little carbohydrate — see the [Glycemic Load Calculator](/glycemic-load-calculator/) to calculate this for any food and serving size.
Favoring low-GI foods, especially in combination with fiber, protein, and fat, is a commonly used strategy for smoothing post-meal blood glucose spikes. However, GI values are just one factor among many — total carbohydrate amount, portion size, and food combinations all matter for blood sugar management.
No — published GI values are averages from controlled studies and can vary based on ripeness, preparation method, individual digestion, and what other foods are eaten at the same time. They're best used as general guidance rather than precise predictions for any specific meal.
White bread is made from refined flour with most of the fiber-rich bran and germ removed, so its starch is digested and absorbed quickly, producing a fast, sharp rise in blood glucose. Whole grain and higher-fiber breads generally have somewhat lower GI values as a result.
Cooking method changes how accessible a food's starch is to digestive enzymes — for instance, al dente pasta has a lower GI than very soft-cooked pasta, and cooling cooked starchy foods like rice or potatoes can lower their GI through a process called starch retrogradation. Riper fruit also tends to have a higher GI than less-ripe fruit.
Diets higher in low-GI foods have been associated with better long-term blood sugar control in some research, making GI one tool people use alongside the [Diabetes Risk Calculator](/diabetes-risk-calculator/) when evaluating overall dietary patterns. This calculator is educational and does not replace personalized dietary guidance from a healthcare provider or registered dietitian.
Not necessarily — high-GI foods eaten in small portions, combined with protein, fat, or fiber, or consumed around exercise can have a smaller practical impact than the GI value alone suggests. Total diet quality and glycemic load matter more than avoiding any single high-GI food.
Also known as
GI calculatorglycemic index food chartlow GI foods calculatorGI lookup toolglycemic index chart