The useful answerRice cooker keep-warm cost depends on its average holding power and the time food stays in that mode. A hypothetical 25 W average for eight hours adds 0.20 kWh, or $0.036 at $0.18/kWh. That is separate from the energy used to cook.

Create two readings

To answer the holding question, record cumulative kWh when cooking finishes and again when the warm period ends. Subtract the first reading from the second. Measuring only the total session cannot tell you how much belongs to cooking versus holding.

Keep the lid use and quantity reasonably consistent between trials. Opening the cooker repeatedly to inspect a meter or change the test conditions makes the result less representative of an ordinary day. Use only a compatible, appropriately rated measurement setup.

Translate holding energy into a budget

Suppose the cooking stage consumes 0.30 kWh and eight hours of holding consume another 0.20 kWh. At the illustrative rate of $0.18/kWh, the stages cost 5.4 cents and 3.6 cents, respectively. The complete session costs 9 cents.

Over 20 similar days, cooking costs $1.08 and holding costs $0.72. These invented measurements illustrate the calculation; they do not establish a typical wattage or a safe holding duration for a particular cooker.

Do not confuse watts with food temperature

Low electricity consumption does not prove that a warm setting maintains a suitable food temperature. Follow the cooker’s holding instructions and food-safety guidance. If you change your routine, plan appropriate storage and reheating rather than leaving cooked rice in a switched-off appliance. The FDA source below provides general refrigeration and leftover-handling guidance, not a test of your cooker’s warm mode.

Compare realistic routines

Compare cooking close to mealtime with cooking earlier and holding, using the schedule your household can actually follow. A storage-and-reheating alternative has its own electricity use and practical requirements. Include that reheating energy instead of assigning it zero. If the difference is only a few cents per day, reliability and a workable food-handling routine may matter more than buying a different cooker to chase a small estimated saving.

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Sources & further reading

Numerical examples are illustrative unless explicitly described as measured. This guide does not claim hands-on product testing. Read the methodology and editorial disclosure.