Glycemic Load Calculator
Estimate how a serving of food is likely to affect your blood sugar. Enter its Glycemic Index and net carbs, or search our food database by portion size, and get an instant Low, Medium or High result.
Know the Glycemic Index and the net carbs in your serving? Enter them below to get the Glycemic Load directly.
Not sure of a food's Glycemic Index? Search our food database, enter how much you'll eat, and we'll work out the carbs and the Glycemic Load for you.
Weigh your portion or use the weight on the package. We use the food's carbs per 100 g (net carbs when we have its fiber value) to work out the carbs in your portion. Foods marked “est.” don't have a lab-tested GI yet.
What Is a Glycemic Load Calculator?
A Glycemic Load (GL) calculator estimates how much a specific serving of food is likely to raise your blood sugar. It combines two pieces of information: the food's Glycemic Index (GI), which measures how fast its carbohydrates are digested and absorbed, and the actual amount of carbohydrate in the portion you eat.
Glycemic Index alone can be misleading. Watermelon, for example, has a high GI, but a typical serving contains so little carbohydrate that its real-world impact on blood sugar is small. Glycemic Load corrects for this by factoring in portion size, giving a more realistic picture of how a food will actually affect you.
How the Calculation Works
Glycemic Load is calculated with a simple, widely used formula:
GL = (GI × Net Carbs in grams) ÷ 100
Once calculated, the result is classified into one of three ranges so you can interpret it at a glance:
Low: 10 or below · Medium: 11–19 · High: 20 or above.
The calculator rounds the result to the nearest whole number before it picks a band, so 10.4 counts as low and 19.6 counts as high.
How to Calculate Glycemic Load, Step by Step
You only need two numbers and a calculator. Here's the routine we follow:
- Find the food's GI. Use a lab-tested value where you can. Our Glycemic Index chart marks which values are tested and which are estimates.
- Work out the carbs in your portion. Use net carbs (total carbohydrate minus fiber) if the label lists fiber. For a weighed portion: carbs per 100 g × grams you'll eat ÷ 100.
- Multiply and divide. GI × carbs in grams ÷ 100. That's the Glycemic Load.
White rice: 150 g of boiled white rice has about 44 g of carbohydrate. With a GI of 73, that's 73 × 44 ÷ 100 = 32. A high GL.
Apple: a small apple (150 g) has about 21 g of carbohydrate and close to 4 g of fiber, so roughly 17 g of net carbs. With a GI of 36, that's 36 × 17 ÷ 100 = 6.1. A low GL.
Honey: one tablespoon (21 g) has about 16 g of carbohydrate. The 2008 international GI tables give honey an average GI of 61, so 61 × 16 ÷ 100 = 9.8.
Glycemic Index vs. Glycemic Load — What's the Difference?
Glycemic Index (GI): a ranking, on a scale where pure glucose is 100, of how quickly a carbohydrate-containing food raises blood glucose compared with pure glucose, tested on a fixed 50g-carbohydrate portion regardless of how much of that food a person would realistically eat.
Glycemic Load (GL): a measure that adjusts GI for your actual serving size, giving a more practical estimate of a real meal's likely effect on blood sugar. That's why GL is usually the more practical number for an everyday meal.
Just need a food's raw GI value rather than its full Glycemic Load? Try our Glycemic Index Chart to look one up directly.
How to Calculate the Glycemic Load of a Meal
Work out the GL of each food on the plate, then add them together. Take a simple oatmeal breakfast:
40 g rolled oats (dry), about 23 g net carbs, GI 55: 55 × 23 ÷ 100 = 12.7
1 small banana (100 g), about 20 g net carbs, GI 51: 51 × 20 ÷ 100 = 10.2
1 cup whole milk (244 g), about 12 g carbs, GI 39: 39 × 12 ÷ 100 = 4.7
Meal total: about 28
Two things to keep in mind. The 10 / 11–19 / 20 bands were written for single servings, so a full meal will often come out above 20. And a real meal usually raises blood sugar less than the sum suggests, because fat, protein and fiber slow digestion. The Linus Pauling Institute at Oregon State University notes that in one study, a meal's GI calculated from the GI values of its individual foods overestimated the measured GI by 22 to 50 percent.
Glycemic Load Chart of Common Foods
GL for a typical serving of everyday foods. The GI values are lab-tested averages from the 2008 international tables. Net carbs are the total carbohydrate in our food database minus fiber from the USDA nutrient database; the two foods marked * have no fiber data yet, so their total carbs are used.
| Food | Serving | GI | Net carbs (g) | Glycemic Load |
|---|---|---|---|---|
| Carrots, boiled | 1/2 cup (80 g) | 39 | 4.8* | 1.9 Low |
| Orange | 1 medium (130 g) | 43 | 12.2 | 5.2 Low |
| Lentils | 3/4 cup (150 g) | 32 | 18.1 | 5.8 Low |
| Apple | 1 small (150 g) | 36 | 17.1 | 6.2 Low |
| Sweet corn | 1/2 cup (80 g) | 52 | 13.5 | 7.0 Low |
| Watermelon | 1 cup diced (150 g) | 76 | 10.8 | 8.2 Low |
| Mango | 3/4 cup (120 g) | 51 | 16.1 | 8.2 Low |
| Pineapple | 3/4 cup (120 g) | 59 | 14.0 | 8.3 Low |
| Chickpeas | about 1 cup (150 g) | 28 | 29.7 | 8.3 Low |
| Honey | 1 tablespoon (21 g) | 61 | 16.0 | 9.8 Low |
| White bread | 1 slice (30 g) | 75 | 14.6 | 10.9 Medium |
| Oatmeal (rolled oats) | 1 cup cooked (250 g) | 55 | 20.2* | 11.1 Medium |
| Banana | 1 medium (120 g) | 51 | 24.2 | 12.3 Medium |
| Sweet potato, boiled | 1 medium (150 g) | 63 | 25.7 | 16.2 Medium |
| Potato, boiled | 1 small (150 g) | 78 | 23.1 | 18.0 Medium |
| Cornflakes | 1 cup (30 g) | 81 | 25.9 | 21.0 High |
| White rice, boiled | about 1 cup (150 g) | 73 | 43.8 | 32.0 High |
Want a food that isn't listed? Search it in the calculator above, or browse the full Glycemic Index chart.
What Your Result Means, and Where Glycemic Load Falls Short
A low GL means a serving of that food is likely to have a small effect on blood sugar. A high GL means the same serving is likely to push blood sugar up more. It's an estimate for a food and a portion, not a measurement of your own response.
GL has real limits. GI values shift with ripeness, processing and cooking, so a banana with brown spots or rice that's been cooked soft can behave differently from the tested sample. People also respond differently to the same food: in a 2015 study of 800 adults, blood sugar after identical meals varied widely from person to person. And GL says nothing about protein, vitamins, fat quality or sodium.
If you have diabetes or take medicine that lowers blood sugar, use GL alongside the carb plan your doctor or dietitian gives you, not instead of it.
Frequently Asked Questions
A Glycemic Load of 10 or below is considered low, 11 to 19 is medium, and 20 or above is high. Keeping individual servings in the low-to-medium range is a simple way to use these bands day to day.
Glycemic Load is often considered more practical because it factors in both the quality of the carbohydrate (GI) and the actual amount eaten, while GI alone reflects speed of digestion regardless of portion size.
This calculator is an educational tool, not medical advice. It can help you understand how different foods may affect blood sugar, but you should always work with your doctor or a registered dietitian for diabetes management.
Net Carbs generally means total carbohydrates minus fiber, since fiber has minimal effect on blood sugar. If you already know a food's net carbs, enter that number directly into the calculator above.
Yes. Cooking time, ripeness, processing, and even cooling and reheating (as with rice or potatoes) can raise or lower a food's GI, sometimes significantly, which is why lab-tested values are the most reliable reference.
GI testing is done on real human subjects, and results can vary by ripeness, brand, preparation, and the reference food used — so a small range of published values for the same food is normal.
Yes. Watermelon has a GI of 76, but a cup of diced watermelon (150 g) has only about 11 g of net carbs, so its GL is about 8. That's why GL is usually the better guide to a real serving.
Glycemic load is defined with available carbohydrate, which leaves out fiber, so net carbs (total carbohydrate minus fiber) is the closer match. Our food search uses net carbs whenever we have the food's fiber value from the USDA nutrient database. For foods without fiber data it uses total carbs, so those results can run a little high; if you know the net carbs of your serving, the first calculator gives the more precise answer.
No. A GL of 15 is in the medium range (11 to 19). If a single serving lands in the mid-teens, a slightly smaller portion or adding protein, healthy fat or fiber to the meal usually brings its effect down.
Calculate the GL of each food on the plate and add the numbers together. Expect the total to be higher than the single-serving bands, and remember that fat, protein and fiber in a mixed meal usually make the real effect smaller than the sum.
Medical & Scientific References
The formula, the Low / Medium / High bands and the example values on this page come from these sources:
- Atkinson FS, Foster-Powell K, Brand-Miller JC. International Tables of Glycemic Index and Glycemic Load Values: 2008. Diabetes Care. 2008;31(12):2281–2283.
- Foster-Powell K, Holt SHA, Brand-Miller JC. International table of glycemic index and glycemic load values: 2002. Am J Clin Nutr. 2002;76(1):5–56.
- Linus Pauling Institute, Oregon State University. Glycemic Index and Glycemic Load.
- Zeevi D, et al. Personalized Nutrition by Prediction of Glycemic Responses. Cell. 2015;163(5):1079–1094.
- University of Sydney. Glycemic Index Research and GI Database.
- USDA FoodData Central (carbohydrate and fiber values used in the examples).
Medical disclaimer: This tool is provided for general educational purposes only and does not constitute medical advice. It is not a substitute for professional diagnosis or treatment. Always consult a qualified healthcare provider or registered dietitian regarding any medical condition, including diabetes or prediabetes.