Start with the reference amount: US labels give values per serving, EU and UK labels per 100 g. Then check calories against the portion you will really eat, look at protein and fibre, and keep an eye on saturated fat, added sugars and salt. Salt equals sodium × 2.5, and 5% DV is low, 20% DV high.
Key takeaways
- US labels are per serving; EU and UK labels are always per 100 g or 100 ml.
- Multiply the label by the servings you actually eat, not the servings printed.
- Salt = sodium × 2.5; WHO advises under 5 g of salt (2,000 mg sodium) a day.
- On the FDA's %DV scale, 5% or less per serving is low and 20% or more is high.
- EU labels show total sugars only, so check the ingredients list for added sugar.
What should you look at first on a nutrition label?
Start with the reference amount, not the calories. Every number on the label describes a specific quantity of food, and that quantity changes from country to country. In the United States, the Nutrition Facts panel is built around a serving size and tells you how many servings the package holds. In the EU and the UK, the nutrition declaration is always given per 100 g or per 100 ml, and sometimes per portion as well.
Per 100 g lets you compare two products fairly, such as two cereals or two pasta sauces. Per serving tells you what one sitting provides, but only if your portion matches the pack's.
| Feature | US Nutrition Facts | EU / UK nutrition declaration |
|---|---|---|
| Main reference | Per serving (with servings per container) | Per 100 g or 100 ml, sometimes per portion |
| Energy | Calories (kcal) | Kilojoules (kJ) and kilocalories (kcal) |
| Sugars | Total sugars, with added sugars shown separately | Carbohydrate, "of which sugars" (total sugars) |
| Salt | Sodium in mg | Salt in g |
| Percentages | % Daily Value (%DV) | % Reference Intake (%RI), often on the front |
Why does the serving size matter so much?
According to the US Food and Drug Administration (FDA), the serving size reflects the amount people typically eat or drink. It is not a recommendation of how much you should eat. Everything else on the panel, from calories to sodium, refers to that one serving.
The catch is the number of servings per container. If a bag of crisps lists 150 kcal per serving and 3 servings per bag, eating the whole bag means 450 kcal, not 150. Some larger US packages carry a dual-column label showing values per serving and per package.
The NHS gives the same warning for UK labels: a manufacturer's idea of a portion may be different from yours. If you pour cereal straight from the box, your bowl may hold twice the portion printed on the side. Weighing it once or twice is a quick reality check; our guide to portion sizes without a scale has hand-based shortcuts if you do not own one.
How do you read calories and kilojoules?
Calories on a label are kilocalories (kcal). EU and UK labels must show energy in both kJ and kcal; 1 kcal is about 4.2 kJ, so a label reading 1,680 kJ is roughly 400 kcal.
You can also sanity-check calories from the macronutrients. Protein and carbohydrate provide 4 kcal per gram and fat 9 kcal per gram. Take a homemade granola bowl with yogurt, nuts and fruit, which Sporty's per-serving estimate puts at 420 kcal, 14 g protein, 52 g carbs and 18 g fat:
- Protein: 14 g × 4 = 56 kcal
- Carbohydrate: 52 g × 4 = 208 kcal
- Fat: 18 g × 9 = 162 kcal
- Total: 426 kcal, close to the 420 kcal estimate
Small gaps come from rounding and from fibre providing less energy. Real values depend on the recipe and portion. For more on how the three macros fit into a day, see macros explained.
What do the fat, carbohydrate and protein lines tell you?
Fat is shown as total fat with saturated fat underneath ("of which saturates" in Europe). The FDA lists saturated fat as a nutrient most people should eat less of, with a Daily Value of 20 g. US labels also show trans fat.
Carbohydrate on a US label is total carbohydrate, including fibre and sugars. On EU labels, fibre is listed on its own line when it is declared. In both cases, the sugars line sits inside the carbohydrate total, not on top of it.
Protein is the simplest line; comparing protein per 100 kcal across similar products helps if you want to stay full on fewer calories.
How do you tell total sugars from added sugars?
This is one of the biggest differences between label systems. A US label shows total sugars and then "Includes X g Added Sugars", with a Daily Value of 50 g. An EU or UK label shows only "of which sugars", which is total sugars: the natural sugars in milk and fruit plus anything added.
The 50 g figure lines up with the World Health Organization's advice to keep free sugars below 10% of energy: on a 2,000 kcal day, 10% is 200 kcal, or 50 g of sugar. On European labels, the ingredients list is your best clue to added sugar. Ingredients are listed in descending order by weight, so if sugar, syrup or honey appears near the start, a large share of the sugars is probably added. Our article on sugar limits and hidden sources lists the many names sugar hides under.
How do you convert sodium to salt?
US labels list sodium in milligrams; European labels list salt in grams. To go from sodium to salt, multiply by 2.5. WHO's figures show the relationship: 5 g of salt contains 2,000 mg of sodium, so 1 g of salt holds 400 mg of sodium.
| Guideline | Sodium | Salt equivalent |
|---|---|---|
| WHO adult limit | under 2,000 mg | under 5 g |
| US Daily Value | 2,300 mg | about 5.75 g |
| NHS adult maximum | about 2,400 mg | 6 g |
Most people eat far more. WHO reports that adults worldwide averaged about 4,278 mg of sodium a day in 2021, roughly 11 g of salt, more than double its limit. In many countries much of it comes from processed foods, so the salt line is worth checking.
What do %DV and %RI mean?
The percentage column shows how much of a daily reference amount one serving provides. In the US it is the % Daily Value, based on 2,000 kcal a day as a general guide. The FDA's rule of thumb is simple:
- 5% DV or less per serving is low.
- 20% DV or more per serving is high.
Use it to aim lower on saturated fat, sodium and added sugars, and higher on fibre (Daily Value 28 g), vitamin D, calcium, iron and potassium. A cereal with 20% DV fibre per serving gives about 5.6 g; for why that matters, see how much fibre you need.
In Europe, front-of-pack labels often show % Reference Intake, the share of an average adult's daily guideline amount in one portion. Your own needs depend on age, sex, size and activity, so treat both percentages as comparison tools, not personal targets.
How do UK traffic-light labels work?
Many UK packs add red, amber and green colour coding to the front. Red means high, amber medium and green low. The NHS uses these thresholds for foods per 100 g (drinks use different ones):
| Per 100 g | Low (green) | High (red) |
|---|---|---|
| Total fat | 3 g or less | more than 17.5 g |
| Saturated fat | 1.5 g or less | more than 5 g |
| Sugars | 5 g or less | more than 22.5 g |
| Salt | 0.3 g or less | more than 1.5 g |
A red light does not make a food off limits; it suggests smaller amounts or less often, balanced with other choices that day.
What is a quick 30-second label routine?
- Check the serving size and servings per container, or switch to the per 100 g column.
- Read calories and compare them with the portion you will actually eat.
- Look at protein and fibre for staying power.
- Check saturated fat, added sugars and salt (or sodium × 2.5).
- Scan the first three ingredients.
Dishes you cook at home or order in a restaurant have no label at all. That is where photo logging in Sporty can give you a per-serving estimate to work with. If you have a medical condition that needs strict sodium, sugar or protein limits, such as kidney disease, ask a doctor or registered dietitian how to apply these numbers to you.
Frequently asked questions
Is per 100 g or per serving better?
Per 100 g is best for comparing two similar products fairly. Per serving is useful for estimating one sitting, but only if your portion matches the one printed on the pack.
How do I convert sodium to salt?
Multiply sodium by 2.5. For example, 400 mg of sodium is 1 g of salt, and WHO's limit of 2,000 mg sodium equals 5 g of salt a day.
What does 20% DV mean?
It means one serving provides a fifth of the Daily Value, based on a 2,000 kcal diet. The FDA treats 20% DV or more as high and 5% DV or less as low.
Why do EU labels not show added sugars?
EU and UK labels list total sugars under carbohydrate, which includes natural milk and fruit sugars. Check the ingredients list: if sugar or syrup is near the top, much of the sugar is added.
Sources
This article is general information, not medical advice. If you have a health condition, are pregnant or under 18, talk to a doctor or registered dietitian before changing your diet.