By Zencalcy Editorial TeamLast reviewed About us
Glycemic index ranks carbohydrate-containing foods by how quickly they raise blood glucose compared with a reference food. This calculator uses a small table of common reference values, then combines the selected GI with the carbohydrate in your portion to estimate glycemic load. Both the index category and the load are shown.
Look up a food's GI and calculate its glycemic load.
GL = GI × available carbohydrate(g) ÷ 100
The table uses common reference GI values: white bread 75, oats 55, lentils 32, apple 36 and boiled potato 78. Actual values vary with variety, cooking and testing method. GI bands used here are low at 55 or below, medium from 56 to 69, and high at 70 or above.
| Symbol | Meaning |
|---|---|
| GI | Glycemic index of the selected food. |
| carbohydrate | Grams of available carbohydrate in the portion. |
| GL | Glycemic load for that portion. |
White bread has a GI of 75, which is high. GL = 75 × 30 ÷ 100 = 22.5, also a high load. An apple with GI 36 and 20 g of carbohydrate gives GL 7.2, a low load, and oats at GI 55 with 40 g gives GL 22.0 even though the GI sits at the top of the low band.
A short table cannot cover every food, and it should not be treated as a complete diet guide. Its value is in showing that foods with similar carbohydrate content can behave differently. Lentils and apples sit low, white bread and boiled potato sit high, and oats land in between. Portion size can overturn the ranking: a large serving of a low-GI food may still produce a substantial glycemic load. Preparation matters too, since pasta cooked al dente and pasta cooked soft do not behave identically. If you use GI to plan meals, combine it with carbohydrate counting and, where available, your own glucose response. The table is a starting point for comparison, not a verdict on whether a food belongs in your diet.
Continue with the Blood Sugar Converter, Estimated Average Glucose Calculator, or the A1c Calculator — or browse more diabetes tools and all health calculators.
Low is 55 or below, medium is 56 to 69 and high is 70 or above. These are common reference bands. The category describes the food's effect per fixed amount of carbohydrate, not the effect of a realistic portion.
These tools convert or screen laboratory values using published formulas. They do not diagnose diabetes, insulin resistance or ketoacidosis, and they do not calculate an insulin dose. Laboratory methods vary; confirm results with the reporting lab and a clinician. DKA symptoms need urgent medical care.
Reference material used to build and check this calculator:
Last reviewed: September 2026. See how we build and check every tool on the about page.
Content updated: September 2026