How to Read Nutrition Labels
Start with the serving size, match it to the amount you eat, then read the calories and nutrients. A large protein number is only useful when you know how much food it describes.
Read the serving before the protein number
A Nutrition Facts panel describes a stated amount of food. If the amount you eat differs, the energy and nutrient amounts differ too. The FDA explains that a serving reflects what people typically consume; it is not a personal recommendation. This guide uses the U.S. Nutrition Facts format. [1]
- Find the serving size and servings per container.Read the quantity and its unit, then check how many servings the package holds. One packet and one serving can be different amounts.
- Match it to the amount you will eat.For the practice food above, a 225 g portion is 1.5 times the printed 150 g serving. Check whether the package also supplies a per-container column before doing the calculation.
- Scale the numbers together.Multiply the calories, protein and other nutrient amounts by the same serving multiplier. Keep the original units attached to every result.
- Read beyond the headline nutrient.Use the rest of the panel to check the nutrients relevant to your needs. The protein line is one part of the food's nutrition information.
Work through a portion you can check
Here is our fictional example in full. The values are invented so you can practise the arithmetic without mistaking them for a food-composition record.
| Item | Printed serving | Multiply by 1.5 |
|---|---|---|
| Food amount | 150 g | 225 g |
| Energy | 180 calories | 270 calories |
| Protein | 12 g | 18 g |
| Total carbohydrate | 24 g | 36 g |
| Total fat | 4 g | 6 g |
The calculation: portion amount ÷ printed serving amount = serving multiplier. Keep the units the same: 225 g ÷ 150 g = 1.5. Then 12 g of protein × 1.5 = 18 g of protein.
Try it: what if you eat only 75 g?
75 ÷ 150 = 0.5 serving. The example portion contains 90 calories, 6 g protein, 12 g carbohydrate and 2 g fat. Every nutrient amount uses the same one-half multiplier.
What % Daily Value tells you
% Daily Value (%DV) puts a nutrient amount in context using a daily reference. It is different from the number of grams in the serving. The FDA's general guide considers 5% DV or less low and 20% DV or more high, for an individual nutrient per serving. [2]
Read that percentage alongside the nutrient name. “High” fiber and “high” sodium describe different things. The FDA generally advises choosing more dietary fiber, vitamin D, calcium, iron and potassium, and less saturated fat, sodium and added sugars. Your individual dietary needs still matter. [2]
The percentages do not add up to a score
Each %DV compares one nutrient with its own reference amount. Do not add the column to get a product rating. The 2,000-calorie reference used for general label advice also does not establish your personal calorie requirement. [1]
Compare foods on the same basis
Before comparing two protein numbers, check the amounts of food behind them. A larger serving can show more protein simply because it contains more food. Convert both to the same amount when the labels allow it.
For another fictional example, Food A lists 12 g protein per 150 g, while Food B lists 10 g per 100 g. Food A works out to 8 g per 100 g: 12 ÷ 150 × 100. On that shared basis, Food B supplies more protein. The original 12-versus-10 comparison was misleading because the serving amounts differed.
This is a protein comparison, not an overall judgment about the foods. Check the rest of the panel, the portion you want and how the food fits your needs. FDA label guidance recommends comparing similar products using the same serving size. [1]
Label questions that cause confusion
Why does protein sometimes have no %DV?
That does not mean the food contains no protein. For products aimed at the general population aged four and older, a protein %DV is not always required when no protein claim is made. Read the grams on the protein line; label rules include exceptions. [1]
Should I add total sugars and added sugars together?
No. Added sugars are already included in total sugars. Treating them as two separate amounts would count the added portion twice. [1]
Does the serving size tell me how much I should eat?
No. It gives the amount used for the label's information and reflects typical consumption. Your portion may differ. Match the numbers to that portion before using them in your plan.
Sources
- FDA: How to Understand and Use the Nutrition Facts Label — serving size, calories, sugars, nutrient comparisons and protein %DV.
- FDA: What's on the Nutrition Facts Label — the reference values and their interpretation.
The diagrams, practice-food values and calculations on this page were created for this guide. They do not reproduce an FDA sample label or a manufacturer's product.