Glycemic Load Calculator

GL = (GI × available carbs in serving) ÷ 100 — total daily glycemic load for up to 6 foods. Harvard / Sydney University GI database values.

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How to use this calculator

  • Pick up to 4 foods from the dropdowns.
  • Set servings (a "serving" matches the parenthetical size in each option label — e.g. 1 slice of bread, 1 cup of rice).
  • For foods not in the list, you can't enter custom — for that, the formula is straightforward: GL = (GI × carbs in grams) / 100.
  • Compare meal GL to the < 10 / 10-19 / ≥ 20 per-meal bands.

About this calculator

Glycemic Load (GL) was introduced by Salmerón et al. (1997 JAMA) to fix a problem with the original Glycemic Index (GI): GI tells you the rate at which a food's carbs raise blood glucose, but it doesn't tell you how much carb is in a normal portion. Carrots have a moderate GI (~35) but only 11 g of carbs per cup — their glycemic load is tiny (3.9). White bread has GI 75 and 14 g per slice — GL = 10.5 per slice, dwarfing the carrot impact. The formula is GL = (GI × available carbs in grams in serving) ÷ 100. Per-meal bands from Atkinson et al. (2008 Diabetes Care): < 10 low impact; 10-19 medium; ≥ 20 high. Daily totals from Harvard Health Publishing: < 80 low; 80-120 medium; > 120 high (associated with type-2 diabetes risk in long-term cohort studies). This calculator pulls reference values from the University of Sydney Glycemic Index Database (gisymbol.com) and Harvard's 2024 published table. Individual responses to identical foods can vary by 3-4× (Zeevi et al. 2015 Cell), so these are population averages, not personal predictions.

Frequently asked

GI vs GL — which one matters?+
GL is generally more clinically meaningful because it accounts for serving size. Watermelon has a high GI (~72) but very little carb per serving — its GL is only about 5. White bread has similar GI but 3× the GL per slice. Both metrics are used together in modern dietary guidance.
Why do GI values differ between sources?+
GI is measured by feeding healthy volunteers a portion containing 50 g of available carbs and tracking blood glucose for 2 hours. Differences come from: (1) which reference food (glucose or white bread); (2) ripeness, cooking method, processing; (3) individual variation in test subjects. The University of Sydney database is the most-cited authoritative source.
Does food order matter for GL?+
Yes — Shukla et al. (2015 Diabetes Care) showed that eating protein + vegetables BEFORE carbs reduces post-meal glucose by ~37% vs the reverse order. Total GL is unchanged but the timing/amplitude curve flattens substantially.
Are low-GL diets backed by evidence?+
Cochrane Review 2017: low-GI/GL diets show modest improvement in HbA1c (~0.2-0.5%) for people with type-2 diabetes. They are not silver bullets, but they are evidence-based and broadly endorsed by ADA, EASD, and WHO dietary guidance.
Source?+
Salmerón J et al. (1997), "Dietary fiber, glycemic load, and risk of NIDDM", JAMA 277(6); Atkinson FS, Foster-Powell K, Brand-Miller JC (2008), "International tables of glycemic index and glycemic load values", Diabetes Care 31(12); University of Sydney Glycemic Index Database (gisymbol.com); Harvard Health Publishing "Glycemic index and glycemic load for 100+ foods" (2024 update).

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