About & methodology
Who builds it
I am a student. Like everyone else I watch the supermarket bill climb and struggle to see why. I wanted to know where the money actually goes, so I started looking at the data.
Prices change every day across supermarkets, but it's hard to see where it is actually worth shopping. You cannot easily ask for "ketchup" and find the cheapest one, or build a whole basket and see which supermarket wins overall.
Τιμόμετρο started as my own tool for those questions, and I opened it up because I am not the only one asking them. It is a personal project, with no company, no funding and no relationship with any chain. None of them pays, and none of them can pay, to rank higher.
I will get things wrong. The code detects and flags errors in the data, but it does not catch everything. If you see something wrong, tell me with the "Report a problem" button or through contact.
Why it exists
Comparing prices across supermarkets is challenging because each chain carries exclusive products and different pack sizes. Τιμόμετρο solves this by comparing unit prices and the total cost at checkout.
How we find the cheapest
You say what you want and how much: "10 rolls of toilet paper", "2 litres of milk". We work out, for each supermarket, which packs give you that quantity for the least money.
The point is that we measure what you pay at the till, not the shelf price. One roll of toilet paper at €0.48 looks cheaper than a ten-roll pack at €2.40. But if you want ten rolls, the first option means ten packs in your trolley and €4.80, twice as much.
Two rules keep us from comparing unlike things: we only measure products sharing the same unit (toilet paper is filed sometimes in rolls, sometimes in kilos), and each chain is judged on its own products, so it never loses for not stocking a rival's exclusive item.
How we catch source errors
The source contains real mistakes. A 240 g box of NESCAFE is €19.20 at one chain and €0.21 at another, a per-sachet price recorded as the box price. Errors like this always win a search for the minimum, so we check:
- each price against the median for the same product across other chains (3+ chains);
- each unit price against the category median, for products sold by only one chain.
Outliers are not deleted, they are excluded from comparisons and shown flagged. Today this affects roughly 1% of prices.
Where the prices come from
Every price carries its own source, which you can see by hovering over it on the product page. Today we use:
- ab.gr — Read from the shop's own website
- bazaar-online.gr — Read from the shop's own website
- market-in.gr — Read from the shop's own website
- lidl-hellas.gr — Read from the shop's own website
- mymarket.gr — Read from the shop's own website
- xalkiadakis.gr — Read from the shop's own website
- sklavenitis.gr — Read from the shop's own website
The "Go to shop" link
Next to each result there is a link to the chain's online shop. It simply opens their home page: we do not transfer your basket and we send them nothing about you. There is no commercial arrangement behind that link, we earn nothing if you click it, and it has no effect on the ordering of results. If a partnership is ever added, it will be stated plainly here and beside the link.
What we cannot see
Anything that isn't published on the chains' websites or online stores. If a popular product is missing from a chain's online listing, our suggestion for that chain may differ from the physical store.
How it was built
The code behind Τιμόμετρο was written with the help of Anthropic's Claude Code. The decisions about what we measure, how we measure it and what we publish are mine, as is the responsibility for everything this site says.
Last updated: 20 Sep 2026, Contact