Is a robot vacuum cheaper to run than an upright?

Per session yes, but over a month they land in the same range, because the robot runs far longer.

Each figure above is that appliance at its own typical use, which is why they differ. The reasons below are what actually settle this comparison — the running cost of the electricity each draws is not the whole story.

Why the running cost does not settle robot vacuum versus vacuum cleaner

• A robot draws about 40 W against an upright's 900 W, but cleans for an hour or more instead of fifteen minutes.
• The dock also draws a few watts continuously to keep the battery topped up, which over a year exceeds the cleaning itself.
• Both are small numbers. Neither is a meaningful line on an electricity bill, and the choice should be made on convenience.

Both figures use each appliance’s typical wattage and default usage at the U.S. average of 18.34¢ per kilowatt-hour, and exclude fixed charges, taxes and time-of-use rates. Change the wattage, usage or state on either appliance’s own page to compare them on your terms, or read how to check a running-cost figure before trusting any of them.