This calculator uses Ofgem typical domestic consumption values as a starting point, then adjusts for the number of people in your household using square-root scaling (each additional person adds proportionally less than the first).
Electricity is spread fairly evenly across the year. Gas is heavily seasonal - January and February usage is around 1.6x the annual average, while summer months drop to 0.4x as heating is not needed.
Ofgem Q2 2026 cap rates: Electricity 24.5p/kWh + 61p/day standing charge. Gas 6.24p/kWh + 31p/day standing charge. VAT at 5% is included in these rates.
These are estimates. Your actual bill depends on insulation quality, thermostat settings, appliance efficiency and behaviour. A smart meter will give you exact readings.