• Understand your bill Section

    Separate a rate increase from a usage increase before you blame an appliance or buy anything.

  • Energy tools Section

    Calculators that show their working, so you can check the arithmetic yourself.

  • Buying guides Section

    Research comparisons of exact product variants, with who each one suits and when to buy nothing.

  • Stop drafts Section

    Window and door heat-loss fixes for older homes, for owners and renters.

  • Appliance operating costs Section

    What the appliances you use most cost to run, worked out from the label or a meter reading at your own rate.

  • Electricity cost calculator Tool

    Work out what an appliance costs to run from its watts and hours, or from a kWh reading off a plug-in meter. Uses your own rate and shows the formula.

  • Why is my electric bill so high? Guide

    A short diagnostic: compare kWh per day, billing days and your rate across two bills before blaming an appliance. Includes a worked example and free checks.

  • Plug-in electricity monitors Buying guide

    Kill A Watt P4400 and P4460 versus energy-monitoring smart plugs: what each shows, what it keeps, what it cannot measure, and when to borrow instead.

  • Window insulation for older homes Guide

    Before you buy shrink film: permission, frame finish, a patch test, measurements, window access and removal. For owners and renters of older homes.

  • Window insulation kits compared Buying guide

    3M, Duck and Frost King shrink-film kits compared by exact pack contents, film dimensions, suitable frame surfaces and usable coverage, not just the window count on the box.

  • Refrigerators Guide

    Why a fridge's label watts overstate its use, how to read the EnergyGuide kWh figure, and how to measure it safely.

  • Dehumidifiers Guide

    Rated watts versus real cycling, why humidity and room conditions change the answer, and how to get a measured figure.

  • Freezers Guide

    How to measure an old freezer, what a replacement scenario needs to include, and why not every old freezer should be replaced.

  • Dryers Guide

    Electric, heat-pump and gas dryers compared per load, why a plug-in meter cannot measure a 240 V dryer, and the free changes that cut cost.

  • Space heaters Guide

    The arithmetic for a 1,500 W heater, why a low setting changes heat output not efficiency, and the CPSC direct-to-wall rule.

  • Thermostats Guide

    What has to be true about your schedule, heating system and wiring before a smart thermostat pays back, without a manufacturer's headline percentage.

  • About this site Guide

    Who runs What Does It Cost to Run?, what it covers and what it leaves out.

  • How we research and measure Guide

    Desk research versus testing, which sources we trust, how products are chosen and how corrections work.

  • Corrections and contact Guide

    How to report an error, a changed product or a broken link.