How to read a nutrition label
The numbers on a food label only help if you read them in the right order. Here is how to make sense of serving sizes, calories, the %DV and the ingredient list in under a minute.
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A nutrition label is one of the most useful tools in the supermarket, and one of the most misread. People glance at the calories, miss that the number is for a small serving, and walk away with the wrong idea entirely. Read in the right order, though, the label tells you almost everything you need in about thirty seconds: how much is really a portion, what the calories and key nutrients are, and whether a food is high or low in the things you care about. Here is how to read it properly.
In short: always start with the serving size and how many servings are in the pack, because every other number is per serving. Then check the calories, use the % Daily Value (5 percent or less is low, 20 percent or more is high) to judge nutrients, and glance at the ingredient list, which runs from most to least by weight. To turn this into a daily target, a free calorie calculator tells you how much you actually need.
Start with the serving size, the number everyone misses
The single most important line is at the top: the serving size and the servings per container. Every figure below, including the calories, is for one serving, not the whole pack. This is where most people go wrong. A small bag of chips might say 150 calories, but if the bag holds 2.5 servings and you eat the lot, that is 375 calories, not 150.
So the first question is never "how many calories" but "how many servings am I actually eating". If the serving size is half a cup and you pour a full cup, double every number on the label. Snack packs, drinks and cereals are the usual traps, because the listed serving is often smaller than the amount people really eat in one go.
Calories, and comparing them fairly
Calories tell you how much energy is in one serving. On their own they are neither good nor bad, they are a budget: the calorie calculator works out roughly how many you need in a day, and the label tells you what a food spends against that. The honest way to compare two products is to make sure you are comparing the same amount, which is where serving sizes get slippery, since two brands can quote different serving sizes to make their numbers look better. The fix is in the per-100g section below.
The % Daily Value, and the simple 5 and 20 rule
Next to many nutrients you will see a % Daily Value (%DV). It shows how much one serving contributes toward a day's recommended amount of that nutrient, based on a 2,000 calorie diet. You do not need to add these up precisely. There is a quick rule of thumb the US FDA uses:
- 5 percent DV or less is low in that nutrient.
- 20 percent DV or more is high in that nutrient.
Use it in both directions. For things you want less of (saturated fat, sodium, added sugars) aim for the low end. For things you want more of (fibre, and often calcium, iron, potassium) the high end is good. A hypothetical cereal showing 25 percent DV for added sugars and 4 percent for fibre is telling you something clearly. Note that most US labels do not give a %DV for protein, so judge protein by its grams instead.
What to limit and what to look for
Labels group nutrients into two camps. The ones to limit are usually saturated fat, sodium (salt) and added sugars, because most people already get plenty. The ones to get enough of are dietary fibre, and depending on your diet, protein, calcium, iron, potassium and vitamin D. A food can be low in calories but high in sodium, or high in calories but rich in fibre and protein, which is why the full picture beats the calorie number alone.
A few details help you read them quickly. Total fat is broken down into saturated and trans fat just below it, and those are the ones to limit. Sodium is shown in milligrams, where a common upper guide is about 2,300 mg a day. Protein is listed in grams and often without a %DV, so judge it by the grams against your own target rather than a percentage.
Added sugars versus total sugars
Modern labels split sugar into total sugars and added sugars. The difference matters. Total sugars include the natural sugar in fruit, milk and vegetables, which comes packaged with fibre and nutrients. Added sugars are what is put in during processing, and that is the number to keep low: the World Health Organization suggests keeping free (added) sugars under 10 percent of your daily calories, and ideally under 5. A plain yoghurt has sugar but little or no added sugar, while a flavoured one can carry several spoonfuls of added sugar. If you only read one sugar line, read added sugars.
One regional note: the separate added sugars line is a US and Canadian feature. UK and EU labels list only total "sugars" and do not break out added sugar, so there you check the ingredient list for sugar, syrups and other sweeteners near the top instead.
Do not skip the ingredient list
Below the numbers sits the ingredient list, and it hides a useful trick: ingredients are listed from most to least by weight. So the first two or three ingredients make up the bulk of the food. If sugar, or one of its many names like syrup, dextrose or concentrate, appears near the top, the product is mostly that, whatever the front of the pack claims. A short list of recognisable ingredients is usually a better sign than a long list of unfamiliar ones.
Per serving versus per 100g, and why labels differ by country
This is the part that trips up anyone comparing products, and it splits by region. In the United States the Nutrition Facts label shows everything per serving. In the UK, Europe and much of the world, the label must show values per 100g or per 100ml, and often per serving as well. The UK NHS explains this per-100g format.
The per-100g figure is the honest way to compare two products, because it ignores the serving size each brand chose. If one cereal looks lower in sugar per serving only because its serving is smaller, the per-100g line reveals the truth. When comparing foods, compare per 100g; when planning how much you will actually eat, use the per-serving column. On a US label, which has no per-100g line, you can still compare fairly with a quick sum: take a nutrient's grams per serving, divide by the serving size in grams, and multiply by 100, which puts two products on the same footing.
How to read a label for your goal
What you look for depends on what you are doing. Losing weight: watch the calories per serving against your daily budget, and favour foods high in fibre and protein that keep you full. Managing sugar or diabetes: focus on added sugars and total carbohydrate per serving. On the label, total carbohydrate already includes the sugar, fibre and starch together, so a food showing 30g total carbohydrate and 5g fibre has about 25g of other carbs. Building muscle: scan for protein per serving and treat it like the macros you are tracking. Our guide on how to calculate your macros shows how label numbers feed a daily target, the macro calculator sets that target, and how many calories to lose weight covers the deficit.
This is general information, not medical or dietary advice. Personal targets for calories, carbs and sugar vary a lot, so if you have diabetes, kidney disease, a food allergy or another condition, check with a doctor or a registered dietitian before changing your diet. Figures here were checked against FDA and NHS guidance in 2026.
Common label-reading mistakes to avoid
| Mistake | Do instead |
|---|---|
| Reading calories before the serving size | Check servings per pack first, then multiply |
| Trusting front-of-pack claims like "low fat" | Turn it over and read the actual numbers and ingredients |
| Comparing two foods per serving | Compare per 100g, since serving sizes differ by brand |
| Reading total sugars, ignoring added sugars | Check the added sugars line for processed foods |
| Skipping the ingredient list | Read the first three ingredients, listed by weight |
Frequently asked questions
What should I look at first on a nutrition label?
The serving size and the number of servings per container. Every other figure, including calories, is per serving, so you need this before anything else makes sense.
What is a good or bad % Daily Value?
As a rule of thumb, 5 percent DV or less is low in a nutrient and 20 percent DV or more is high. Aim low for saturated fat, sodium and added sugars, and high for fibre and nutrients you want more of.
What is the difference between total sugars and added sugars?
Total sugars include natural sugars from fruit, milk and vegetables. Added sugars are put in during processing. Health advice is to keep added sugars low, so that is the more important line on a processed food.
Should I compare foods per serving or per 100g?
Per 100g where the label shows it, which most countries outside the US do. Serving sizes vary between brands, so per-serving numbers alone are not a fair comparison. On a US label there is no per-100g line, so divide a nutrient's grams per serving by the serving size in grams and multiply by 100 to compare fairly. Use the per-serving column to plan how much you will actually eat.
How do I read a label for weight loss?
Check the calories per serving against your daily calorie budget, and favour foods high in fibre and protein, which keep you fuller for longer. A calorie calculator sets the budget the label spends against.
Why do labels look different in different countries?
The US Nutrition Facts label is per serving, while the UK, EU and much of the world require values per 100g or 100ml, often with a per-serving column too. The nutrients shown and the rounding rules also vary by country.