About HowMuchToRun

HowMuchToRunhelps people understand exactly how much it costs to run the appliances in their home. A utility bill gives you one big number at the end of the month, but almost no clue about which devices drove it. We built free, instant calculators that turn an appliance's wattage and how you use it into a clear cost per day, month and year — plus the yearly CO₂ footprint that comes with it.

Who is behind the site

HowMuchToRun is published by The HowMuchToRun Team, a small independent group that writes about home energy. We are not a utility, a manufacturer or a retailer, so we have no stake in pushing you toward any particular brand or tariff. Our only goal is to make the cost of electricity easier to reason about. When we recommend an efficient appliance, we say so plainly in our affiliate disclosure.

How our numbers are calculated

Every estimate uses the same transparent formula. We take the appliance's power in kilowatts (watts ÷ 1,000), multiply by the hours it runs per day, then by the days per year it is used, to get annual energy in kilowatt-hours (kWh). Multiplying kWh by your electricity rate gives the cost; multiplying by a grid emissions factor gives the CO₂.

The defaults we start from, all of which you can override:

• Electricity rate: 17¢ per kWh, a representative average. Real rates range from under 11¢ to over 30¢ depending on where you live, so the single most useful thing you can do is enter your own rate from your latest bill.
• Grid emissions: 0.4 kg of CO₂ per kWh, a typical mixed grid. A coal-heavy region will be higher; one rich in hydro, nuclear or renewables will be much lower.
• Wattage and usage: we pre-fill a typical power draw and usage pattern for each appliance, drawn from manufacturer specifications and published energy-use data. These are sensible starting points, not the last word — your specific model and habits matter.

The same calculation powers the on-page calculators and our public API, so the figure you see and the figure we serve to developers can never drift apart. All results are estimates intended for guidance, not exact billing.

Learn more

If you want to go deeper than a single number, our guides explain how to read your electricity bill and how time-of-use tariffs can change what an appliance really costs you.

How we keep the site free

HowMuchToRun is supported by affiliate links and advertising. When we link to an energy-efficient appliance and you buy through that link, we may earn a small commission at no extra cost to you. This never changes the numbers our calculators show. See our affiliate disclosure and privacy policy for the details.

Contact

Questions, corrections or an appliance you'd like us to add? Email hello@howmuchtorun.com or visit our contact page. We read everything and update figures when the evidence supports it.