Electricity bill Calculator
Calculate day/night usage, standing charges and VAT.
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13 free tools
Home energy Calculators
Home energy calculators for electricity, heating, insulation, heat pumps, solar panels, batteries and tariffs. Each calculator explains its inputs, formula and limits.
Appliance running cost Calculator
Estimate electricity use with operating hours and duty cycle.
Open calculator →Heat pump vs boiler Calculator
Compare annual fuel demand, running cost and simple payback.
Open calculator →Insulation heat saving Calculator
Estimate fabric heat loss avoided by improving a U-value.
Open calculator →Room radiator demand Calculator
Size an indicative radiator output from room volume.
Open calculator →Solar PV return Calculator
Estimate self-consumption benefit, export income and payback.
Open calculator →Battery tariff arbitrage Calculator
Estimate savings from storing cheaper electricity for peak use.
Open calculator →Electric shower cost Calculator
Calculate shower electricity, water use and cost per shower.
Open calculator →Water heating time Calculator
Estimate energy and time needed to raise water temperature.
Open calculator →Electricity tariff comparison Calculator
Compare two single-rate offers with standing charges and credits.
Open calculator →Heating oil energy cost Calculator
Convert an oil delivery to useful heat and annual consumption.
Open calculator →Ventilation heat loss Calculator
Estimate air-change heating losses and heat-recovery benefit.
Open calculator →Solar thermal hot water Calculator
Compare potential collector yield with annual hot-water demand.
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