How the estimate works

Example only: a 12 fl oz can of cola has about 37 g of sugar, and all of it is added. 37 ÷ 4.2 is about 9 teaspoons, and about 74% of a 50 g reference.

Added sugar, total sugar and free sugar

Total sugars include the sugar found naturally in fruit and milk. Added sugars are put in during processing or at the table. Honey and syrups count as added sugars. The Nutrition Facts label lists both numbers, but only added sugars have a Daily Value.

The World Health Organization uses a wider group called free sugars. It is the added sugars plus the sugar in fruit juice. If you choose the WHO reference, the calculator counts juice too.

How we estimate added sugar

The USDA records we use list total sugars but not added sugars. So we sort each food in one of four ways:

• No added sugar. Plain foods such as fruit, milk, plain yogurt, vegetables, beans and plain grains.
• All sugars counted as added. Soda, candy, syrups, sweet baked goods and most cereals.
• Plain version subtracted. For foods such as flavored yogurt, chocolate milk and ice cream, we subtract the sugar in the plain food from the same database.
• Share from labels. For a few foods such as jam, milk chocolate and baked beans, we use the added share shown on typical labels.

Results from the last two methods, and all restaurant and mixed dishes, are marked “≈ Estimate”. Recipes and brands vary. When you have the package, the label is the most accurate source, and you can enter it in place of any food.

Glycemic index and glycemic load

The glycemic index (GI) ranks a food from 0 to 100. It compares how much the carbs in the food raise blood glucose over two hours with the same amount of carbs from pure glucose. A GI of 55 or less is low, and 70 or more is high.

Glycemic load (GL) also counts your portion. For one serving of a food, a GL of 10 or less is low, 11 to 19 is medium, and 20 or more is high.

GI values come from the summary table of the International Tables of Glycemic Index and Glycemic Load Values: 2008. When a food was not in that table, we used the closest food in it, the average for its group, or the fallback values the authors suggest (70 for flour products, 40 for vegetables, 30 for dairy foods). Those results are marked as estimates.

Protein, fat, ripeness and cooking all change how a meal acts in the body. Use glycemic load to compare foods and meals. It does not predict your blood sugar reading.

The daily references

• 50 g. The Daily Value for added sugars on U.S. Nutrition Facts labels, based on a 2,000 calorie diet. For one serving of a food, FDA counts 5% of the Daily Value or less as low and 20% or more as high.
• 25 g for women and 36 g for men. The American Heart Association limits, about 6 and 9 teaspoons a day.
• 25 g of free sugars. The World Health Organization says free sugars should stay under 10% of daily energy. It adds that staying under 5%, about 25 g or 6 teaspoons, would bring more benefits.
• 10 g per meal. The Dietary Guidelines for Americans, 2025 to 2030, say no amount of added sugars is recommended as part of a healthy diet, and that one meal should contain no more than 10 grams of added sugars. The calculator checks each meal against this.
• Carbs. No single carb number fits everyone. CDC counts one carb serving as about 15 grams. The American Diabetes Association advises an eating plan made for the person, with carbs that are high in fiber and low in added sugar.
• Fiber. The Daily Value on U.S. labels is 28 g.

The practice score

The score is our own simple tool for practice. It is not a medical measure. Up to 50 points come from added sugar: full points at or under your reference, and none at double it. Up to 25 points come from fiber, with full points at 28 g. Up to 25 points come from the average GI of your carbs, with full points at 55 or less and none at 70 or more. The score does not judge how many carbs you eat. It appears once you log 3 foods.

Where the numbers come from

Food values come from the USDA National Nutrient Database for Standard Reference, Release 28 (SR28). Each result lists the USDA record number, so you can check it.

Food library version 2026.11-r1, built 2026-11-12.

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Sources