Home energy calculators
Bills, appliances, heat pumps, insulation, lighting and standby waste.
Electricity bill calculator
Build your household electricity bill from the appliances you actually use (or from your kWh), with flat, tiered or day/night tariffs, standing charge, levies and VAT. See which devices drive the cost.
Home energykWh & cost calculator
Turn any power rating and running time into kilowatt-hours and money per hour, day, month and year. Optional day/night tariff, plus a quick check of what the same use would cost at other prices.
Home energyAC running cost & size
Sizes an air conditioner for your room (BTU and kW) from floor area, ceiling height, sun exposure, climate and occupants, then calculates the electricity it uses and what it costs per hour, day, month and cooling season from its SEER or EER.
Home energyAppliance energy cost
Enter the wattage and daily use of any device to see its kWh, running cost per hour, day, month and year, plus the CO₂ it emits on your grid.
Home energyWater heater running cost
Works out how much it costs to heat your water each year with six technologies (electric tank, heat-pump water heater, gas tank, gas tankless, electric instant and solar thermal), including standby losses, purchase price and lifetime.
Home energyLED bulb savings
Compare incandescent, halogen or CFL bulbs with LEDs of the same brightness: energy and money saved per year, replacement bulbs avoided, payback time in months, 10-year savings and CO₂. An optional heating-season correction is included.
Home energyStandby power / phantom load
Count the devices in your home that never really switch off (TVs, set-top boxes, consoles, routers, smart speakers, chargers) and see their phantom load in watts, kWh, money and CO₂, plus what smart plugs or power strips could save.