How this calculator works
Glycemic load combines a measured food GI with the available carbohydrate grams in a serving. Unlike GI alone, GL changes with portion size. Use compatible glucose-scale GI values and carbohydrate definitions. A reverse calculation only rearranges the relationship; it does not experimentally measure GI or predict an individual glucose response. The result is an estimate for information only and is not medical advice.
Formula
GL = GI x available carbohydrate(g)/100. GI = 100GL/carbohydrate. Carbohydrate(g) = 100GL/GI.
Worked example
A portion containing 30 g available carbohydrate with GI 50 has GL 15. Doubling it to 60 g gives GL 30 while GI stays 50.
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Frequently asked questions
Can GL be zero?
Yes, if either carbohydrate or GI is zero. Inverse modes require a positive divisor to give a unique answer.
Can I combine portions?
Add the calculated GL contributions of compatible food values. The GI calculator can also show a carbohydrate-weighted meal estimate.
Does low GL mean a food is always healthier?
No. GL does not describe protein, micronutrients, energy density or the whole dietary pattern.