How to use this calculator
Use annual kWh labels for comparable appliances and similar usage. Enter the new purchase and installation cost, any rebate or resale credit, and your comparison period. The calculator compares energy costs with the net purchase cost.
The formula
Annual saving = (old kWh − new kWh) × rate. Simple payback = net purchase ÷ positive annual saving.
Worked example
An old appliance using 700 kWh and a new one using 300 kWh save 64.00 per year at a sample rate of 0.16. A 600.00 purchase less 50.00 credit has a simple payback of about 8.6 years. Over 10 years, keeping costs 1,120.00 and replacing costs 1,030.00.
Assumptions and limitations
Assumes constant electricity rates and usage. Excludes repairs, financing, discounting, tax, fixed charges, disposal costs and future resale. Both appliances are assumed to operate throughout the comparison period. Consider useful life and condition alongside the numbers.
Frequently asked questions
What if the new appliance uses more energy?
Annual savings are negative and there is no payback from energy savings. Credits may still lower total modeled costs, so check both totals.
Does payback tell me when I must replace it?
No. Payback only compares electricity savings with net purchase cost. Condition, reliability, safety, repair costs and expected service life also matter.
Estimates only. Use your utility tariff and appliance energy label for more accurate inputs.