Sources and methodology
The city pages, the hub and the cost-of-living calculator show official data with its source and period. Values are imported automatically from the publishers or entered from their official decisions, checked for completeness and plausibility, and kept with their history; a value that fails the checks is held for a person to review and never shown. No value is computed by an artificial intelligence model.
Sources
Calculations by BWY
- Prices with VAT: KEVR approves electricity, heating, water and gas prices without VAT; the pages add the 20% VAT households pay. The household gas price is the KEVR price plus the transmission charge the end supplier publishes, both without VAT; where the supplier publishes none, the page says so.
- Rank and gap: the district gross wage ranked among the 27 district cities (Sofia with the wage of Sofia city; Sofia district is not ranked separately) and compared with Sofia.
- Changes over 12 months: the annual rates of the harmonised index of consumer prices, national, as Eurostat publishes them.
- Heating in the calculator, by the mode you choose. District heating: the heat NSI reports as delivered to households divided by all district heating customers (about 5 MWh a year, hot water included, a lower bound), with its space-heating share scaled by the district's ten-year heating degree days against the national mean (Eurostat), at the KEVR price with VAT. Electricity and gas: the final energy for space heating per household heated by that fuel (JRC-IDEES of the European Commission, a national model), scaled by the same climate factor, at the tariff with VAT, gas incl. transmission. Wood: the firewood households buy per household (NSI) over the census share of dwellings heated by wood, scaled likewise, at the price households paid. Modelled quantities are shown with a range.
The cost-of-living calculator
The calculator adds official quantities times official prices for the household you describe, line by line, and names every line that has no verified value for the city instead of filling it in. Its method is described on the calculator page.
Licences and reuse
- NSI licence for the use of statistical information, version 2.0
- Eurostat reuse policy (Decision 2011/833/EU)
- European Commission legal notice (CC BY 4.0)
- ECB statistics reuse policy
- Public-sector information (Access to Public Information Act, chapter 3)
- Official acts and registers (Copyright Act, Art. 4)
- Prices published by an energy company (Ordinance No 2, Art. 40)
- BWY listings from partner agencies
- BWY editorial estimate
Eurostat data are reused under the Commission reuse policy (Decision 2011/833/EU); Eurostat bears no responsibility for the calculations BWY makes with them.
Report an error
Found a value that does not match its source? Write to [email protected] with the page and the value; we check it against the source and correct it.