Food & Nutrition

How to Read a Nutrition Facts Label: Serving Size, Sodium and Added Sugars

By Marcus Delgado / November 10, 2026

The Nutrition Facts label is the black-and-white box on the back or side of most packaged foods in the United States. It tells you how much of each nutrient is in one serving. This guide walks down the label from top to bottom, in order, and explains each word the first time it appears. The most useful habits are simple: check the serving size first, use the 5 and 20 rule for percentages, and compare two products using the same amount. This is general information, not medical advice.

Key takeaways

Everything on the label is based on one serving, and a package often holds more than one.
The “% Daily Value” shows how much of a day’s recommended amount one serving gives you. Five percent or less is low. Twenty percent or more is high.
Sodium, saturated fat and added sugars are the lines the FDA lists as ones to get less of.
Fiber, vitamin D, calcium, iron and potassium are lines to get enough of.
Your own doctor or a registered dietitian can tell you what limits fit you personally.

Where to begin: the serving size

Start at the top. You will see two things: the “serving size” and the “servings per container.” The serving size is a standard amount, such as one cup or two cookies. It is set so that similar foods can be compared. It is not a recommendation about how much you should eat, as the U.S. Food and Drug Administration (FDA) points out.

“Servings per container” tells you how many of those servings are in the whole package. The FDA’s example is a frozen lasagna with four servings of one cup each. If you eat two cups, you are eating two servings, so every number on the label doubles.

The label was redesigned in recent years. Serving sizes now reflect how much people actually eat and drink. For instance, the amount used for ice cream rose from half a cup to two-thirds of a cup, and for soda from 8 to 12 ounces, according to the FDA. A package holding one to two servings must generally be labeled as a single serving. Some larger packages show two columns, one for a single serving and one for the whole package, which saves you from doing the multiplication.

Calories

A calorie is a measure of energy in food. Calories now appear in large, bold type just under the serving size. In the FDA’s lasagna example, one serving has 280 calories, two servings have 560, and the whole four-serving package has 1,120.

The FDA uses 2,000 calories a day as a general guide for nutrition advice. It adds that the right amount for you depends on your age, sex, height, weight and activity level. A doctor or dietitian can help with a number that fits you.

The percent Daily Value and the rule of 5 and 20

On the right side of the label is a column headed “% Daily Value,” often shown as %DV. A “Daily Value” is a reference amount for a day, and the percentage tells you how much one serving contributes to it.

The FDA offers an easy rule of thumb:

5% or less per serving is low in that nutrient.
20% or more per serving is high in that nutrient.

That is the whole rule. Whether low or high is good depends on the nutrient. You want a low number for sodium, and a higher number for fiber. The FDA also notes that the footnote at the bottom of the label explains the %DV and the 2,000-calorie guide.

For reference, these are the Daily Values the FDA publishes for several nutrients. They are the base for the percentages on the label.

Nutrient	Daily Value (FDA)
Sodium	2,300 mg
Saturated fat	20 g
Added sugars	50 g
Dietary fiber	28 g
Potassium	4,700 mg
Vitamin D	20 mcg
Calcium	1,300 mg
Iron	18 mg

Nutrients to get less of

The FDA groups three lines as ones to limit. These are the ones to look at closely if you or your doctor are watching them.

Sodium

Sodium is a mineral found in salt. The Daily Value is less than 2,300 milligrams (mg) a day. The FDA says Americans eat about 3,400 mg a day on average, and that over 70% of the sodium in our diets comes from packaged and prepared foods, not from the salt shaker. A diet high in sodium is linked with high blood pressure, which can raise the risk of stroke and heart disease.

In the FDA example, one serving of lasagna has 850 mg of sodium, or 37% of the Daily Value. That is “high” by the rule above. Two servings would be 74%. Whether any particular amount is right for you is a question for your doctor.

Saturated fat

Saturated fat is one type of fat listed under Total Fat. The sample label shows 4.5 grams, which is 23% of the Daily Value, so also “high.” Trans fat and total sugars appear on the label without a %DV.

Added sugars

“Total Sugars” includes sugar that is naturally in foods, such as the sugar in milk or fruit. “Added Sugars” is shown indented underneath it and counts sugar put in during preparation. The FDA says this includes table sugar and other sweeteners, syrups, honey, and concentrated fruit or vegetable juices. Both a gram amount and a %DV are given. The Daily Value for added sugars is 50 grams. The FDA’s lasagna sample has 0 grams.

Nutrients to get enough of

The FDA suggests choosing foods higher in fiber, vitamin D, calcium, iron and potassium more often. In the lasagna sample, fiber is 4 grams (14%), calcium is 320 mg (25%), potassium is 510 mg (10%), iron is 1.6 mg (8%), and vitamin D is 0 mcg (0%).

Two of these lines are newer. Vitamin D and potassium are now required on the label, along with the amount in addition to the percentage. Calcium and iron stay required, and now show the actual amount too. Vitamins A and C are no longer required, though a maker may still list them. Some foods will therefore have fewer vitamin lines than older labels.

A line-by-line table

Label line	What it shows	What to look at
Serving size	A standard amount for comparing foods	Compare it with what you actually eat
Servings per container	How many servings are in the package	Multiply if you eat more than one
Calories	Energy in one serving	Multiply by servings eaten
Saturated fat	One kind of fat	%DV: lower is usually the aim
Sodium	Salt-related mineral, in mg	%DV: 5% or less is low, 20% or more is high
Total Sugars and Added Sugars	All sugars, and sugars added in making	The Added Sugars line and its %DV
Dietary fiber	Fiber in the food, in grams	%DV: higher is the aim
Vitamin D, calcium, iron, potassium	Required minerals and vitamins	%DV: higher is the aim
Footnote	Explains %DV and the 2,000-calorie guide	Read it once; it helps

What “low sodium” and similar words mean

Words on the front of a package have legal meanings. The FDA gives these for sodium, per serving:

Sodium-free or salt-free: less than 5 mg.
Very low sodium: 35 mg or less.
Low sodium: 140 mg or less.
Reduced sodium: at least 25% less sodium than the regular version.
Light in sodium or lightly salted: at least 50% less than the regular version.
No salt added or unsalted: no salt added during processing, but the food may still contain sodium.

“Reduced sodium” can still be fairly high if the regular version was very high. Check the milligrams on the label.

Comparing two products: a worked example

The numbers here are made up to show the method. Suppose you are choosing between two canned soups. Each label lists a serving as one cup.

Soup A: 480 mg sodium per serving, which is 21% DV. The can holds 2.5 servings.
Soup B: 140 mg sodium per serving, which is 6% DV. The can also holds 2.5 servings.

Because both use the same serving size, you can compare them directly. Soup A is high by the 20% rule and Soup B is just above the low line. If you eat the whole can of Soup A, that is 2.5 servings, or about 1,200 mg, around 52% of the Daily Value in one bowl. The same can of Soup B would be about 350 mg. The method is the point: same amount, then compare.

Shopping checklist

Read the serving size and servings per container first.
Multiply the numbers if you eat more than the serving size.
Compare two products using the same serving amount.
Use the 5 and 20 rule on sodium, saturated fat and added sugars.
Look at Added Sugars, not only Total Sugars.
Look for higher %DV of fiber, calcium, potassium and vitamin D.
Read the sodium milligrams even when the front says “reduced.”
Bring your doctor’s or dietitian’s limits, if you have them.
Take a magnifying glass or use your phone camera zoom if the print is small.

Frequently asked questions

Is the serving size how much I should eat?

No. The FDA says the serving size is a standard amount to help compare foods, not a recommendation of how much to eat.

What does %DV mean?

It shows how much of a nutrient one serving contributes to a total day’s diet. Five percent or less is low and 20% or more is high.

What is the difference between total sugars and added sugars?

Total sugars include sugars found naturally in a food. Added sugars are the ones put in during processing or preparation, such as sweeteners, syrups and concentrated juices. Both appear on the label, with added sugars shown underneath.

Do I need to follow 2,000 calories a day?

The FDA calls 2,000 calories a general guide only. Needs vary by age, sex, height, weight and activity. Ask your doctor or a dietitian.

Before you decide

You do not need to read every line each time. Check the serving size, then the sodium, added sugars and saturated fat, then glance at fiber, vitamin D, calcium and potassium. If you have a health condition or take medicines, your doctor or a registered dietitian can set personal limits and tell you which lines matter most. The label is a tool, and you are the one who decides.