How to compare two products by their labels: six steps with a worked example
Two nutrition tables are comparable only when they describe the same weight, the same state of the product and the same units. On a shelf that is almost never the case, so you first bring the numbers to a common basis and only then look at the result. Below are six steps and one example with made-up numbers.
The example used in the steps
Two breakfast products on a shelf. The numbers are invented and serve only the arithmetic.
| A: flakes | B: granola | |
|---|---|---|
| Table given per | 40 g serving | 100 g |
| Energy | 150 kcal | 410 kcal |
| Protein | 3 g | 14 g |
| Fat | 1 g | 14 g |
| Carbohydrate | 32 g | 56 g |
| Pack and price | 500 g, 150 ₽ | 300 g, 240 ₽ |
Step 1. Bring both tables to 100 g
The Eurasian regulation TR CU 022/2011 (text on the EEC website, part 4.9, item 3), which applies to food sold in Russia, lets a manufacturer give nutrition values per 100 g or 100 ml "and/or" per serving. A table per serving only is legal, and it cannot be compared with a per-100-g table without conversion.
The conversion is simple: divide the value by the serving weight and multiply by 100. For flakes A, energy is 150 ÷ 40 × 100 = 375 kcal per 100 g, protein 7.5 g, fat 2.5 g, carbohydrate 80 g. Granola B needs no conversion: 410 kcal, 14 g, 14 g, 56 g. In the per-100-g column, A is 35 kcal lighter.
Step 2. Make sure the products are in the same state
For food the consumer prepares, values are declared without the effect of preparation (part 4.9, item 11). The figures on a pack of cereal, pasta or a dry mix describe the dry product. Dry oats cannot be compared with cooked porridge: the water in porridge makes the per-100-g figures much lower for the same food. Compare dry with dry and cooked with cooked.
The "per 100 g" and "per 100 ml" columns are not interchangeable either. Compare drink with drink and solid with solid. Weighing raw versus cooked food is covered in raw or cooked weight.
Step 3. Put energy in the same units
Energy may be given in joules and calories; Russian packs usually show the pair "kJ / kcal". If only kilojoules are shown, divide by 4.1868, the factor used in the regulation (Annex 2). Dividing by 4.2 is enough for a rough check. For example, 1600 kJ is about 382 kcal.
Step 4. Check each table against itself
Energy on a label is calculated from protein, fat and carbohydrate using the factors in Annex 4 of the regulation: 4, 9 and 4 kcal per gram. The check takes half a minute.
- A: 7.5 × 4 + 2.5 × 9 + 80 × 4 = 30 + 22.5 + 320 = 372.5. The table says 375. It matches.
- B: 14 × 4 + 14 × 9 + 56 × 4 = 56 + 126 + 224 = 406. The table says 410. It matches.
A small gap is normal: values are rounded (Annex 3), and fiber, polyols and organic acids use their own factors. If the gap is large and there is no fiber or polyol in the ingredients, check whether one of the numbers belongs to a different weight, such as a serving. Why label figures are never exact is covered in label accuracy.
Step 5. See what the calories are made of
Two servings with similar energy can be built differently. The share of calories from protein is worked out the way the regulation defines its protein claims: protein × 4 ÷ energy. For A that is 30 ÷ 375 = 8%. For B it is 56 ÷ 410 ≈ 14%. For reference, the regulation allows the words "high protein" from 20% of energy (Annex 5).
Fat and carbohydrate work the same way. In B, fat supplies about a third of the calories (126 ÷ 410 ≈ 31%); in A, about 6% (22.5 ÷ 375). This describes the makeup of the food and does not rank it. What matters depends on why you are choosing.
A "of which sugars" line is not on the regulation's mandatory list (part 4.9, item 1), so sugar in both products has to be found in the ingredients. The names it hides under are covered in hidden sugar.
Step 6. Recalculate for your serving and your money
The serving a manufacturer names may differ from yours. Suppose you pour 60 g of each.
| Per 60 g | A: flakes | B: granola |
|---|---|---|
| Energy | 225 kcal | 246 kcal |
| Protein | 4.5 g | 8.4 g |
| Cost of a serving | 18 ₽ | 48 ₽ |
The price per kilogram is 300 ₽ for A and 800 ₽ for B, so 60 g costs 300 × 0.06 = 18 ₽ and 800 × 0.06 = 48 ₽. The energy gap shrank from 35 kcal per 100 g to 21 kcal per serving, while the price gap per serving is 2.7 times. Estimating a portion without scales is covered in portion size, and the traps of unit prices in price per kilogram.
What a comparison does not settle
A table describes quantity, not suitability for a particular person. Fewer calories does not mean better, and more protein does not mean right for you. With diabetes, an allergy, pregnancy, or a diet plan from a doctor, choose by that plan rather than by two numbers. Ingredients, allergens and additives are not part of the nutrition table and are read separately: see checking ingredients in ten seconds.
Labeling rules are quoted from the regulation text as of October 2026.
Frequently asked questions
- Which column should I compare: per 100 g or per serving?
- Start with per 100 g or per 100 ml, because manufacturers choose different servings. If there is no per-100-g column, divide the value by the serving weight and multiply by 100. Then recalculate for the serving you actually eat.
- Can I compare dry cereal with cooked?
- No. For food the consumer prepares, values are declared without the effect of preparation, meaning for the dry product. Compare dry with dry and cooked with cooked.
- How do I convert kJ to kcal?
- Divide by 4.1868, the factor used in the regulation, or by 4.2 for a rough check. For example, 1600 kJ is about 382 kcal.
- How can I check that the numbers in a table are consistent?
- Protein × 4 + fat × 9 + carbohydrate × 4 should roughly equal the energy value. A small gap comes from rounding and fiber. A large gap in a simple product suggests the numbers refer to different weights.
- How do I calculate the share of calories from protein?
- Multiply grams of protein by 4 and divide by the energy for the same weight. The regulation uses a threshold of 20% of energy for a "high protein" claim.
Read next
- How to read the nutrition facts table: per 100 g or per serving — To compare products, use the “per 100 g” column, but calculate how much you’ve eaten based on the actual weight of the portion consumed.
- Calories and macros on the label: why the numbers don't match reality — The same buckwheat in three different apps gives three different calorie counts, and the package shows a fourth.
- Price per kilogram: the only comparable figure on a price tag — There are two numbers on a price tag.
- What to look for in an ingredient list in ten seconds — Reading an entire ingredient list at the shelf is impossible: the print is small, and there is no time.
This article is for general information. It is not medical advice, a diagnosis, or a prescription for treatment or a diet, and it does not replace a consultation with your doctor. If you have a health condition, are pregnant, take medication, or follow a diet prescribed to you, decisions about food belong with your doctor.
Figures from regulations, guidelines and studies are given as they stood when this article was prepared and may since have changed; check them against the primary sources. This article is not advertising, an offer, or individual advice, and neither the author nor the site owner is responsible for decisions taken on the basis of it.