Nutrition & Food Science
What ‘Energy Per 100g’ Really Means
The “per 100g” value is a standardised way to compare foods regardless of pack size. Learn how to use it to judge energy density and per-serve totals.
Nutrition labels often list values “per 100g,” which can be confusing if you’re not familiar with the format. This measurement is simply a standardised way to compare foods, regardless of serving size or packaging.
“Energy per 100g” shows how many kilojoules or calories are in 100 grams of the product. This allows you to compare two foods directly, even if one comes in a 375g pack and the other in a 500g pack. It’s especially useful when comparing snacks, cereals, sauces, and ready-made meals.
For example, if one product has 450kJ per 100g and another has 650kJ per 100g, the second is more energy-dense. This doesn’t mean it’s unhealthy — just that it contains more energy per gram.
When calculating nutrition per serve, you can use the per-100g values to estimate totals based on the portion you actually eat. Tools like RecipeMaths make this process easier by converting label values into per-serve numbers automatically.
Understanding per-100g measurements helps you make clearer comparisons and choose foods that match your dietary goals.