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Energy Consumption Calculator (Appliance kWh)

Quick answer

Add up appliance energy use: kWh = watts x hours/1000 per device, then daily, monthly, and annual totals plus cost at your electricity rate.

Figures are estimates from this calculator’s standard formula — adjust the inputs in the tool below for your exact number.

How Does the Energy Consumption Calculator Work?

kWh = W × h ÷ 1000

Every appliance converts watts and hours into kilowatt-hours on your bill. The calculator sums each device with kWh = W x h/1000, then prices the total. Example: a fridge cycling 150 W at 33 percent duty uses 150 x 24 x 0.33/1000 = 1.19 kWh/day; a 55 W TV on 5 h adds 0.28; a 10 W router never sleeps and adds 0.24. Together about 1.7 kWh/day - 51 kWh and 10 USD a month at 0.20 USD/kWh. Meter cross-check closes the loop: if your computed total says 620 kWh/month and the bill reads 650, the missing 5 percent is usually standby loads nobody listed - a quick audit wins the argument.

  1. 1

    List appliances

    Watts and hours per day.

  2. 2

    Enter your rate

    Price per kWh from your bill.

  3. 3

    Read totals

    Daily, monthly, annual kWh and cost.

Use Cases

Home energy audits before investing in solar

Verifying submetered landlord charges

Comparing old vs new appliance energy labels

Common Mistakes

  • Using nameplate watts for cycling devices like fridges and compressors without duty factor

  • Forgetting always-on loads: routers, smart speakers, and standby chargers

  • Averaging seasonal loads: AC in summer and heating in winter need separate rows

FAQs

Which appliances use the most electricity?

Heating and cooling lead: AC 1-2 kWh/h, water heater 4 kWh/h, dryer 3 kWh/cycle. Then refrigeration (1-2 kWh/day), always-on electronics (0.2-0.5 kWh/day), and lighting (0.1-1 kWh/day depending on LED adoption).

How much does standby power cost?

A typical home leaks 30-60 W continuously: TVs, chargers, set-top boxes. That is 0.7-1.4 kWh/day, 25-50 kWh/month - roughly 5-10 USD monthly at 0.20 USD/kWh. Smart power strips pay for themselves within a year.

How do I lower my consumption cheaply?

LED swaps save 85 percent per bulb; washing at 30 C cuts cycle energy about 40 percent; a 2 C higher AC setpoint saves 6-8 percent per degree. These three moves typically trim 10-20 percent off a household bill with zero equipment cost.

Do smart plugs really save energy?

They save by switching off standby loads: a 3 W phantom load per plug times ten devices is 2.6 kWh/month. The plug's own 1 W consumption nets most of that back, so the real win is automation of heaters and AC schedules.

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