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Data and calculation methods

FATSL methodology

How we calculate prices, macros, rankings, food comparisons and city figures.

Formulas100 g, 100 kcal, 10 g protein
Datareference entries
Reviewinternal review
Limitationsclearly stated

Understanding the calculations

Each explanation below relates to tools and pages you can use on the site.

What is FATSL? FATSL is a reference tool for comparing food macros, calculated costs, city prices and rankings. It presents calculations based on available data; it is not an online shop.
How prices are calculated A price entry links a food, city, unit, currency and recorded amount. If that entry is missing, no price is substituted or invented.
What cost per 100 g means Cost per 100 g puts prices on the same weight basis. Divide a price per kilogram by 10 to make foods easier to compare.
What cost per 100 kcal means Cost per 100 kcal uses the price per 100 g and calories per 100 g. No result is shown if the calorie value is missing or zero.
What cost per 10 g of protein means Cost per 10 g of protein uses the price per 100 g and protein per 100 g. No result is shown if protein is missing or zero.
How rankings work Rankings sort foods by the selected value: price, calories, protein, sugar, fat or calculated cost of protein or calories. Missing values appear below available ones and are never filled with invented numbers.
How food comparisons work A food comparison brings macros, a recorded price or an average across available cities, and calculated costs into one table. Results describe the numbers: higher, lower, nearly equal or unavailable.
How city comparisons work City pages compare only entries available in FATSL. A highlighted minimum is the lowest available value among the selected cities, not a verified current shop price.
What a reviewed entry means Some nutrition values have been reviewed internally to match a specific food and preparation. They remain reference values and may differ from a particular pack, variety or cooking method.
What reference entries mean Some entries support catalogue coverage and navigation checks. They do not confirm market prices and should be read as reference values with limited applicability.
Limitations to keep in mind FATSL does not provide medical advice, promise health benefits or offer a shop checkout. Current shop prices require a separate data review before they can be presented as such.

Explore the data

Nutrition dataMacros, preparation and limitations Price methodologyCity prices and unit conversion FATSLIM referenceValues, formulas and limitations Calculated cost per 100 kcalFormula, worked example and limitations Price per 10 g proteinCalculate from price and protein How the data worksNutrition and prices without guesswork Data limitationsUnderstanding missing and incomplete values rankings proteinA cost-per-10-g-of-protein example Food comparisonTwo foods and their values

Methodology topics

What is FATSL?How the calculation works How prices are calculatedHow the calculation works What cost per 100 g meansHow the calculation works What cost per 100 kcal meansHow the calculation works What cost per 10 g of protein meansHow the calculation works How rankings workHow the calculation works