Watts and kWh are different
Watts measure power; kWh measures energy used. A 1,000 W device used four hours on each of 30 days consumes 120 kWh.
ENERGY COST CALCULATOR
Your home energy costs:
where could you start saving?
Compare appliance costs and experiment with changes in use.
MY ENERGY PLAN
Home savings lab
These are illustrative inputs. Replace them with label or measured data. High power alone does not prove waste.
Appliance costs calculated at a flat unit rate.
Not your household's actual bill.
Saved in this browser only. No cross-device sync; clearing browser data can erase it.
BUY OR KEEP?
Replace it or keep using it?
Use an appliance's replacement button to copy its inputs below.
How to read the numbers
Check the product label
Rated power may differ from actual average use. Air conditioners and refrigerators do not always run at full output. Measured averages improve the estimate.
A new product is not always cheaper overall
Lower electricity costs may take time to repay the purchase. This comparison assumes the entered month repeats throughout the period.
Formulas and assumptions
Monthly kWh = watts ÷ 1,000 × daily hours × days per month.
Monthly electricity cost = monthly kWh × unit rate.
Total cost = purchase + monthly electricity cost × 12 × years.
Payback = B's extra purchase cost ÷ monthly electricity savings. Repairs, resale and rate increases are excluded. Seasonal devices need a different number of usage months.
Privacy and service information
Appliance inputs and rates are stored in this browser and are not sent for calculation. Analytics requires permission. This is not an official utility calculator.