- 1Enter the appliance rated power in Watts (W) from its nameplate or manual.
- 2Enter the average active operating hours per day.
- 3Enter your electricity tariff rate ($ / kWh).
- 4Review the calculated daily, monthly, and annual operating cost breakdown.
The Appliance Cost Calculator estimates electrical energy expenses for individual household appliances based on power rating and daily usage patterns.
Daily kWh = (Power in Watts × Operating Hours per Day) / 1,000
Daily kWh = (W × h) / 1,000Monthly kWh = Daily kWh × 30.4375 | Annual kWh = Daily kWh × 365.25
Monthly kWh = Daily kWh × 30.4375 | Annual kWh = Daily kWh × 365.25Cost ($) = Energy Consumption (kWh) × Rate ($ / kWh)
Cost = kWh × Electricity RateDaily kWh = (200 × 8) / 1000 = 1.6 kWh/day → Daily Cost = 1.6 × 0.15 = $0.24
Monthly kWh = 1.6 × 30.4375 = 48.7 kWh → Monthly Cost = $7.31
Annual kWh = 1.6 × 365.25 = 584.4 kWh → Annual Cost = $87.66Daily kWh = 1500 × 4 / 1000 = 6; Daily cost = 6 × 0.14 = 0.84; Monthly = 6 × 30.4375 × 0.14; Annual = 6 × 365.25 × 0.14Daily kWh = 60 × 5 / 1000 = 0.3; Annual kWh = 0.3 × 365.25 ≈ 109.6; Annual cost = 109.6 × 0.20- Duty cycling: Cycling appliances (refrigerators, air conditioners) do not run compressors 24 hours a day. Input the effective daily active hours rather than 24 hours.
- Standby power excluded: Unmodeled phantom draw or standby power when turned off is not included unless added to active wattage.
- Nameplate rating vs average draw: Most appliances list maximum peak wattage on their label. Average running power may be lower.
Should I enter 24 hours for a refrigerator?
No. Refrigerators cycle their compressor on and off. Most household refrigerators run actively for about 6 to 10 hours per day total.
Is standby power included in the cost calculation?
No. The calculator models energy strictly from the entered power rating and operating hours.
How does it convert watts to kilowatt-hours?
Daily kWh = power (W) × hours per day ÷ 1000. Monthly figures multiply the daily value by 30.4375 and annual figures by 365.25.
Can hours per day be more than 24?
No. Hours per day must be between 0 and 24, and power and the price per kWh must be zero or positive.
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