How the Nutrition Label Numbers Are Calculated

We turn your recipe into a Nutrition Facts label in five steps. Every step is a plain calculation you can check by hand.

Where the numbers come from

The nutrient values come from USDA FoodData Central, the US government database of food composition. We search the Foundation and SR Legacy data sets first, because they hold laboratory analysed foods. You can switch to branded products for a packaged ingredient.

FoodData Central lists nutrients per 100 grams of food. We keep each answer in our own database for 90 days, so a repeat lookup is fast and does not depend on the USDA site being up.

How we calculate one label

1. Read the recipe. We split each line into an amount, a unit and a name. You see every row and can correct it.
2. Find the grams. Weights convert directly. For cups, spoons and counts such as "1 large egg", we use the household measures USDA lists for that food. If a food has no measure for your unit, the row asks you for grams.
3. Add the nutrients. For each ingredient we multiply the USDA value per 100 grams by your grams and divide by 100. We add the results across the recipe.
4. Divide by servings. The total divided by your servings per container gives the amount in one serving. If you enter the weight after cooking, the serving weight uses it. The nutrient totals do not change.
5. Round the FDA way. Each value follows its own rule from 21 CFR 101.9(c). The % Daily Value uses the rounded amount and the FDA daily values for a 2,000 calorie diet. The rounding guide lists every rule.

The ingredient list puts the heaviest ingredient first, as the FDA asks. The allergen line under it prints only the answers you gave.

How accurate are the results?

They are estimates. The FDA accepts values calculated from a database for most foods, but several things can move the real numbers:

• USDA lists an average food. Your flour, butter or chocolate can differ, especially branded ones.
• Cooking loses or concentrates some nutrients. We do not adjust for it.
• If USDA has no value for a nutrient, we count it as zero and show a warning on that ingredient.
• A unit converted through a household measure, such as a cup of flour, depends on how the flour was packed.

Use a laboratory analysis if you make a nutrient content claim, such as "low fat", if you sell widely, or if your product is far from average foods. Our disclaimer says the same in short form.

What we do not do

We do not approve labels, we do not decide your allergens, and we do not tell you whether your state requires a panel. You answer the nine allergen questions before every download and confirm that the label is your responsibility.

Ready to try it? Use the nutrition facts label generator.