How to Read a Nutrition Label

A nutrition label can look like a dense table of numbers, but you rarely need to interpret every number at once.

A more useful approach is to read it in a consistent order:

1. identify what quantity the values describe
2. check energy
3. look at the nutrients relevant to your goal
4. convert the values to the amount you will actually eat
5. compare products on the same basis

This guide focuses on the nutrition declaration itself. Ingredient order and ingredient identification are a separate topic.

First: know what the numbers refer to

Before looking at calories, protein or sugar, find the basis of the nutrition information.

On food sold in the EU, nutrition values are normally shown per:

• 100 g for solid foods
• 100 ml for liquids

A manufacturer may also provide information per portion.

This distinction matters because 100 g is not necessarily the amount you eat.

If a cereal contains 380 kcal per 100 g and your portion is 50 g, your portion provides approximately:

380 × 0.50 = 190 kcal

Reading the quantity basis first prevents one of the most common label-reading mistakes.

What an EU nutrition declaration normally includes

For most prepacked foods requiring a nutrition declaration in the EU, the mandatory declaration includes:

• energy
• fat
• of which saturates
• carbohydrate
• of which sugars
• protein
• salt

Other information, such as fibre, may also be shown voluntarily.

A typical table might look like this:

Do not judge the product from one number alone. The usefulness of each value depends on the food, the amount eaten and the rest of your diet.

Step 1: check the quantity basis

Suppose two products show:

Product A: 170 kcal per portion

Product B: 150 kcal per portion

It is tempting to assume Product B contains fewer calories.

But imagine:

• Product A portion = 100 g
• Product B portion = 70 g

Now compare both per 100 g:

• Product A = 170 kcal per 100 g
• Product B = about 214 kcal per 100 g

The original comparison was mostly a comparison of different portion sizes.

For product-to-product comparisons, per-100-g or per-100-ml values are usually the simplest common basis.

Step 2: read energy correctly

Energy may be displayed in both:

• kilojoules (kJ)
• kilocalories (kcal)

In everyday calorie tracking, “calories” usually refers to kilocalories.

If a label says:

840 kJ / 200 kcal per 100 g

and you eat 150 g:

200 × 1.5 = 300 kcal

If you eat 40 g:

200 × 0.4 = 80 kcal

The label gives the energy density. Your portion determines the energy you actually consume.

Step 3: look at fat — then saturates

The label separates total fat from saturated fat.

For example:

Fat: 12 g

of which saturates: 3 g

The 3 g of saturates is already part of the 12 g total fat. Do not add them together.

This same “of which” logic appears elsewhere on labels.

Step 4: understand carbohydrate and sugars

A label might say:

Carbohydrate: 48 g

of which sugars: 12 g

The 12 g of sugars is included within the 48 g of carbohydrate.

Again, you should not calculate 48 + 12.

Also, the “sugars” line is not automatically the same as “added sugar.”

Sugars may come from ingredients that naturally contain sugars as well as from sugars added during production.

To understand where sugars come from, you often need to look at the ingredient list as well as the nutrition declaration.

Step 5: check protein in context

Protein is normally shown in grams.

For example:

Protein: 18 g per 100 g

If you eat 150 g:

18 × 1.5 = 27 g protein

This calculation is useful when comparing products or tracking a meal.

But a higher protein number does not automatically make one product the better choice in every situation. You may also care about:

• total portion
• energy
• fibre
• salt
• saturated fat
• ingredients
• price
• how the food fits into the meal

Use protein as one part of the comparison rather than as the only criterion.

Step 6: read salt, not just sodium

EU nutrition declarations generally state salt.

That is important when comparing information from different countries or databases because some systems display sodium instead.

Salt and sodium are related, but they are not the same number.

When comparing two EU packages, compare the salt values directly if both labels use salt.

Step 7: check fibre when it is listed

Fibre may appear on the nutrition table even though it is not part of the basic mandatory EU nutrition declaration.

For example:

Fibre: 7 g per 100 g

If fibre matters to your comparison, this can be useful.

But absence of a fibre line does not necessarily mean the food contains no fibre; the manufacturer may simply not provide that voluntary value on the label.

Per 100 g vs per serving

This is one of the most useful distinctions on any food label.

Per 100 g

Best for:

• comparing similar products
• understanding energy density
• comparing protein concentration
• comparing sugar, salt or saturated fat on the same basis

Per serving

Best for:

• estimating what you actually consume
• logging a known portion
• understanding the contribution of one realistic eating occasion

The two columns answer different questions.

For more detail, see Portion Size vs Serving Size: What’s the Difference?.

Example: yogurt comparison

Imagine two yogurts.

If your goal is simply to compare the nutrition declarations, Yogurt A provides more protein and less energy per 100 g in this example.

But the table still does not tell you everything.

You might also check:

• ingredients
• actual portion eaten
• price
• taste
• whether either product is fortified
• how the yogurt fits into the rest of the meal

A nutrition label is useful evidence, not a complete verdict on a food.

Example: cereal with a small listed portion

Suppose cereal contains:

390 kcal per 100 g

The package also lists:

117 kcal per 30 g portion

That arithmetic is correct:

390 × 0.30 = 117 kcal

But if you actually pour 60 g into your bowl, your intake is:

390 × 0.60 = 234 kcal

The manufacturer's portion is a reference quantity. Your actual portion is what matters when estimating your intake.

Example: a product sold in a 250 g package

The label states:

160 kcal per 100 g

The package contains 250 g.

If you eat the entire package:

160 × 2.5 = 400 kcal

If you eat half:

160 × 1.25 = 200 kcal

This is why package size, serving size and amount eaten should not be treated as interchangeable.

A quick formula for any nutrient

If the label gives a value per 100 g:

amount consumed = value per 100 g × grams eaten ÷ 100

Example:

Protein = 12 g per 100 g

Amount eaten = 175 g

12 × 175 ÷ 100 = 21 g protein

The same calculation works for:

• calories
• fat
• saturated fat
• carbohydrate
• sugars
• protein
• fibre
• salt

For liquids, use the same logic with values per 100 ml and the number of millilitres consumed.

How to compare two products fairly

Use this sequence:

1. Put them on the same basis

Compare:

• per 100 g with per 100 g
• or per 100 ml with per 100 ml

Do not compare one product per serving with another per 100 g.

2. Decide what actually matters for this food

For bread, you might care about fibre, salt and energy.

For skyr, you may be particularly interested in protein.

For a sauce, salt, energy and portion size may matter more.

For nuts, a high calorie value per 100 g is expected and does not by itself make them a poor food choice.

3. Consider the amount you will eat

A nutrient concentration and a real-world portion are different questions.

4. Check the ingredient list if necessary

The nutrition table tells you quantities of nutrients.

The ingredient list tells you what the food is made from.

They complement each other.

What does “% reference intake” mean?

Some packages also show percentages based on reference intakes for an average adult.

You might see a presentation such as:

Energy: 200 kcal — 10% RI

The percentage is a reference tool, not a personalized target.

Individual energy and nutrient needs vary.

It can be useful for quickly seeing how a stated portion contributes to the reference amount used on the package, but it should not be interpreted as a precise personal prescription.

Front-of-pack information vs the full nutrition table

Some products show simplified nutrition information on the front of the package.

This can make quick comparisons easier.

However, the full nutrition declaration usually provides more detail.

If the front says something like:

• high protein
• low fat
• source of fibre

you can turn the package over and inspect the actual nutrition table and ingredient list.

Claims and front-of-pack information should not replace reading the underlying data when the details matter to you.

Nutrition claims have specific meanings

In the EU, claims such as:

• low sugars
• high fibre
• source of protein
• high protein

are regulated claims with conditions attached to their use.

They are not simply informal descriptions chosen freely by a manufacturer.

Even so, a claim highlights one characteristic of a food.

For example, “high protein” tells you something about protein; it does not automatically describe the product's entire nutritional profile.

“No added sugars” does not mean “no sugars”

These statements answer different questions.

A product labelled no added sugars may still contain naturally occurring sugars.

The nutrition table's “of which sugars” line shows the total sugars covered by that declaration, not simply sugars added during manufacturing.

This is a common reason to use both:

• nutrition declaration
• ingredient information

rather than relying on one phrase on the front of the package.

Low fat does not automatically mean low calorie

Fat contains substantial energy, so reducing fat can reduce a product's energy density.

But a “low fat” claim does not guarantee that the product is low in calories compared with every alternative.

Other energy-containing nutrients still contribute.

If calories matter to your comparison, check the energy value directly.

High protein does not mean unlimited portions

A product can be protein-rich and still provide substantial energy.

For example, some:

• cheeses
• nuts
• protein bars
• meat products

may contain meaningful amounts of protein while also being energy-dense.

Protein and calories answer different questions.

Check both when both matter to your goal.

Do not judge foods by sugar alone

The sugar line is useful, but foods with similar sugar values can be nutritionally different.

For example, two products may both contain 8 g of sugars per 100 g while differing in:

• protein
• fibre
• energy
• saturated fat
• salt
• ingredients

Likewise, naturally occurring sugars and added sugars are not distinguished simply by looking at the total sugars number.

Use the full context.

Do not judge foods by calories alone

Two foods with the same calories per 100 g can differ considerably in:

• protein
• fibre
• fat
• micronutrients
• water content
• ingredients
• typical portion size

Calories describe energy.

They do not summarize every nutritional property of the food.

How to read a label in 20 seconds

When you are shopping and do not want to study every line, use this sequence:

1. Check per 100 g or per 100 ml.

This establishes the comparison basis.

2. Check calories.

Especially if energy intake matters to your goal.

3. Check the two or three nutrients relevant to this product.

For example:

• protein and sugars for yogurt
• fibre and salt for bread
• saturated fat and salt for cheese
• protein and calories for a protein snack

4. Check your likely portion.

A food eaten in 20 g and a food eaten in 250 g have very different real-world contributions.

5. Look at ingredients when the composition matters.

This prevents the nutrition table from being interpreted in isolation.

Reading labels for calorie tracking

If you are logging food, the most important steps are often:

1. find calories per 100 g
2. determine how many grams you actually ate
3. calculate the calories for that amount

Example:

Label = 240 kcal per 100 g

Amount eaten = 65 g

240 × 65 ÷ 100 = 156 kcal

If your tracking app already contains the exact product, verify that the stored nutrition values match the current package when something looks wrong.

For packaged foods, the current label can be a useful reference when a database entry is missing or outdated.

Reading labels for macro tracking

The same process applies to macros.

Suppose the label gives per 100 g:

• protein: 20 g
• carbohydrate: 12 g
• fat: 8 g

You eat 150 g.

Your portion contains approximately:

• protein: 30 g
• carbohydrate: 18 g
• fat: 12 g

You do not need a separate formula for each macro. Multiply each per-100-g value by the same portion factor.

Reading labels when losing weight

A nutrition label can help with weight-management decisions, but it should not be reduced to “choose the product with fewer calories.”

Useful questions include:

• How large is my realistic portion?
• How much energy does that portion provide?
• Does the food provide protein or fibre that fits the meal?
• Will I eat it alone or with other foods?
• Is the lower-calorie option actually satisfying and practical for me?

The label provides data. Your overall eating pattern provides context.

Reading labels when choosing higher-protein foods

Compare protein on a common basis first.

For example:

Product A: 10 g protein per 100 g

Product B: 15 g protein per 100 g

Then check the actual portion.

If Product A is normally eaten in a 200 g portion, that provides 20 g protein.

If Product B is normally eaten in a 100 g portion, that provides 15 g.

Per-100-g concentration and protein per eating occasion are both useful, but they answer different questions.

Reading labels when choosing higher-fibre foods

When fibre is listed, compare products per 100 g first.

Then consider the portion you actually eat.

A bread containing 7 g fibre per 100 g does not give you 7 g of fibre if you eat only 40 g.

The actual amount would be:

7 × 0.40 = 2.8 g fibre

Again, concentration and portion both matter.

Reading salt values

Salt can become easy to overlook because the numbers are often small.

For example:

0.3 g salt per 100 g

and

1.5 g salt per 100 g

may not look dramatically different at first glance, but the second product contains five times as much salt by weight.

When comparing similar foods, using the same 100-g basis makes these differences easier to see.

What the nutrition label cannot tell you

A nutrition table is powerful, but limited.

It cannot tell you:

• whether you will enjoy the food
• how filling you personally find it
• whether the portion shown matches your portion
• how the food fits into your whole day
• whether the price fits your budget
• whether the food is convenient for your routine

It also should not be used as a single-number scoring system for whether a food is “good” or “bad.”

A practical supermarket comparison

Imagine you are choosing between two packaged lunches.

Lunch A, per 100 g

• 145 kcal
• 5 g fat
• 1.2 g saturates
• 16 g carbohydrate
• 3 g sugars
• 8 g protein
• 0.7 g salt

Package: 300 g

Lunch B, per 100 g

• 120 kcal
• 3 g fat
• 0.8 g saturates
• 14 g carbohydrate
• 2 g sugars
• 7 g protein
• 0.5 g salt

Package: 450 g

If you eat the entire package:

Lunch A:

145 × 3 = 435 kcal

8 × 3 = 24 g protein

Lunch B:

120 × 4.5 = 540 kcal

7 × 4.5 = 31.5 g protein

Lunch B has fewer calories per 100 g but the larger package provides more calories if you eat all of it.

This is why both the standardized comparison and the actual portion matter.

A reusable label-reading checklist

Before buying or logging a packaged food, ask:

1. Are the values per 100 g, per 100 ml or per serving?
2. How much am I realistically going to eat?
3. What are the calories for that amount?
4. Which nutrients matter most for this particular food?
5. Am I comparing products on the same basis?
6. Does the ingredient list add information I need?
7. Am I interpreting a front-of-pack claim too broadly?

If you can answer those questions, you can extract most of the useful information from a nutrition label without turning every shopping trip into a nutrition analysis.