Use this appliance wattage calculator with running watts, daily use, and electricity rate to estimate daily and annual energy use and cost. If the nameplate lists amps and volts instead, switch entry modes and the calculator estimates watts from those values.
Turn one nameplate into a yearly cost you can trust
Start with running power from the nameplate, manual, EnergyGuide label, or a plug-in meter. Then enter how long the appliance runs and the price you pay per .
Starting surge is a separate generator-sizing concern.
Enter dollars per from your bill, not a national average.
The default duty cycle is 1; use the optional factor for a load that regularly switches off.
Example: a 50% duty-cycle scenario
- A 200 W appliance with a user-entered 0.5 duty-cycle factor averages 100 W across its 24-hour use window.
- Over 365 , the estimate is 876 .
- At 0.17/, the annual energy cost is 148.92.
- The 50% factor is an example input, not a universal appliance preset.
Where to read the power figure
Watts measure power at an instant. measure energy over time. A 1,000 appliance running for one hour uses 1 ; multiplying that energy by your per- rate produces the energy-cost estimate.
When the duty-cycle factor matters
A duty-cycle factor reduces the running wattage for a device that switches on and off during the stated use window. Optional standby watts are counted during the remaining hours of the and shown separately in the result details.
Why this is not a generator sizing calculator
Generator selection must account for simultaneous loads and the short starting surge of motors and compressors. This page estimates ordinary energy use and cost from running power, so it intentionally does not recommend a generator size.
Frequently asked questions
Where do I find an appliance's wattage?
Check the data plate or nameplate on the appliance, usually on the back, bottom, side, or inside a door. It lists the rated watts for most models, and the same figures appear in the owner's manual specifications if the label is worn off.
How do I get watts when the label lists only amps and voltage?
Switch to amps-and-voltage mode and enter both nameplate values. The calculator multiplies them for a practical wattage estimate. For some AC loads, true watts can be lower because power factor is not modeled, so measured wattage is better when available.
How do I estimate what it costs to run an appliance?
Multiply the appliance's watts by its daily hours of use to get watt-hours, divide by 1,000 for , then multiply by your utility rate. The calculator runs this chain and scales it to a full . Because real runtime and rate plans shift, treat the result as a close estimate rather than an exact bill.
Does standby power change the yearly total?
Yes. Many appliances keep drawing a few watts while plugged in but not in use, and that idle draw adds up over the hours the appliance is off each . Enter the standby watts and the calculator charges that phantom load separately from the active running cost.
How much electricity does an appliance use over a ?
Enter running power, daily hours, used per , and your electricity rate. The result includes daily and annual plus operating cost. Starting surge is not included, so use a generator-sizing tool when startup load matters.