How the index is calculated

The index tracks a basket of 9 products. For each product, the median comparison price (e.g. €/kg or €/l) of all price observations is computed every week, separately for S Group and K Group stores.

The index follows each product's price change from week to week. The price level is the average price of the products a chain currently sells. For weeks without a price, a product's price is estimated from how the other products' prices moved, so missing prices and products joining or leaving don't make the index jump. When a pack gets smaller, the change shows as a higher price per kilo. The all-stores figure is the average of the S Group and K Group figures. Lidl prices are not currently included.

Prices are shown per litre.

Prices are collected from the S-kaupat and K-Ruoka online stores. Tracking started December 2023 and the figures update weekly. Latest complete week: week 42 · 12/10/2026.