Know what things really cost before you decide.
Free calculators for energy bills, cars, heating and household money — in your own units and currency, with every formula shown and every default rate sourced and dated.
- Official data sources, dated
- Formulas tested by hand
- Your numbers stay in your browser
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How SmartCost Lab is different
Most cost calculators quietly assume a price for you. We only pre-fill a rate when we can point to the official source and the period it covers — such as the U.S. EIA, Ofgem, Statistics Canada or the Australian Bureau of Statistics — and we print that label right under the input. Where no trustworthy national figure exists, the field starts empty and asks for the number on your bill.
Every calculator lets you compare scenarios side by side, explains its method in plain English, and shares results through a link that leaves out personal figures like income or balances unless you choose to include them. Read our methodology.