Microwave vs Electric Kettle: Which Costs More to Run? (2026)

For boiling water, the kettle wins. It transfers heat directly into the water with almost no loss, while a microwave converts mains power to microwaves at roughly 65 percent efficiency. Boiling a cup in the kettle uses about a third less energy. The microwave wins for heating food, where a kettle is no use at all.

At the hours shown, Microwave costs about $16.74 a year and Electric Kettle about $20.08 in the US.

ApplianceTypical wattsHours a dayPer hourPer monthPer year
Microwave1,000 W$0.18$1.38$16.74
Electric Kettle2,000 W$0.37$1.65$20.08

Each at its own typical daily use, and the microwave also heats food. To boil the same water, the kettle uses about a third less. Edit the hours to match your own use. Costs use the typical wattage of each appliance.

When the microwave makes sense

  • You are heating food, not water
  • You need to defrost
  • You want to heat a small amount of liquid already in a cup

When the electric kettle makes sense

  • You are boiling water for tea, coffee, or cooking
  • You boil water several times a day
  • You want it fast

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