Methodology

How the Skyr Index works

One number per product: how many grams of protein you get for one euro spent on it at the supermarket shelf.

The metric

g protein per € = protein per 100 g × pack weight (g) / 100 / price in €
price per 100 g protein = price / (protein in pack) × 100

Higher g/€ means more protein for your money. We also show the price of 100 g of protein in the local currency, which is the same information turned upside down.

What we count

• Skyr only. Products sold as skyr (or Icelandic-style yogurt). Spoonable and drinkable skyr are labelled separately because drinks carry less protein per 100 g.
• Country figures use plain, spoonable skyr at regular price. The country index is the best-value plain skyr; we also show the median of all plain skyr we priced there.
• Regular vs promotional prices. Every price is marked as regular or promo. Loyalty-card-only discounts are ignored (we record the price anyone pays). Promotional prices are shown with a label and left out of country figures; 5 of 180 prices are promos.
• Every price has a date. Prices in this edition were checked between Aug 9, 2026 and Sep 30, 2026. The date is on every product row and page.

Where the numbers come from

• Prices: retailers' own online shops (for example Tesco, Albert Heijn, Frisco, Continente, Kroger), one product page at a time, by hand. For discounters without online grocery (Lidl, Aldi, Biedronka) we use the retailer's own offer page or a reputable price tracker, named in the product's note. Each product page links to its source.
• Protein and other macros: Open Food Facts (ODbL) when the barcode matches and values look sane; otherwise the label shown on the retailer's product page. The source is shown on every product page.
• Exchange rates: ECB euro reference rates of Sep 29, 2026.
• Food price levels (PPP view): Price level index (EU27_2020=100), food and non-alcoholic beverages (A0101), Eurostat prc_ppp_ind, latest year available, retrieved Sep 30, 2026.
• Big Mac prices: The Economist's Big Mac Index (Jul 1, 2026 edition, MIT licence). Euro-area countries use the euro-area price.

The PPP-adjusted view

Euros go further in some countries than others. The adjusted figure multiplies g/€ by the country's food price level index (EU = 100). The result reads as "grams of protein per euro if the rest of this country's food basket cost the EU average". A country that ranks higher on the adjusted view has skyr that is cheap relative to its own food prices. Eurostat publishes no food index for the United Kingdom or the United States in this dataset, so they have no adjusted figure.

Limits

• This is a sample, not a census: 180 products in 19 countries, weighted towards big retailers and best sellers.
• Online prices can differ from store prices and between regions (US prices depend on the store's ZIP code, noted per product).
• Protein values on labels are rounded; Open Food Facts entries can be outdated. We flag known mismatches in the notes.
• We compare price and macros only. Nothing here is health or nutrition advice.

Found a mistake?

Prices change. If you spot a different shelf price, a missing product or a mistake, email us with the store, the product, the price, the date and ideally a photo of the shelf tag. hello@skyrindex.com