Appliance Wattage Calculator

Created by Rahul Dhari
Reviewed by Steven Wooding
Last updated: Nov 11, 2022

This appliance wattage calculator will assist you in estimating the electricity consumption in your house and how much you'll have to pay for it. Your electricity consumption not only depends upon the number of appliances present in the house but also on their wattage and the duration of time they operate. Check out our electricity cost calculator for more.

Appliance wattage in a household differs for different products, say a geyser or water heater has a higher wattage value than a TV. Even though a TV runs for longer, it might consume less electricity than a water heater due to its wattage.

This value is usually stamped on the back or bottom of an appliance and present in the product manuals. However, this remains an estimate of the maximum power a device would draw. The actual wattage value depends on the age, condition, and features and the operating settings of an appliance. Read on to understand how to calculate appliance wattage for your house using our tool. You can find about the reduced value of an appliance from our appliance depreciation calculator.

Interested in other homeowner calculators? Check out our grocery calculator. This calculator is designed to help you to manage your monthly spending.

How to calculate appliance wattage

Before we calculate the consumption of the household, let's take a look at a single device. For an appliance, say an internet or Wi-Fi router having a rated value of WW watts and runs for hh hours, the consumption in kWh for the router would be:

P=W×h1000\quad P = \frac{W \times h}{1000}

Using the above equation, and considering different devices, P1P_1 through PnP_n, the total appliance wattage in household per day, PhP_h is:

Ph=i=1nmiPiPh=i=1nmiWi×hi1000\quad \begin{align*} P_h &= \sum_{i=1}^n m_i P_i \\\\ P_h &= \sum_{i=1}^n m_i \frac{W_i \times h_i}{1000} \end{align*}


  • mim_i – Quantity of ithi^{th} appliance;
  • WiW_i – Wattage (in W) of ithi^{th} appliance; and
  • hih_i – Runtime or usage time (in hours) for ithi^{th} appliance.

Once you know your electricity consumption per day, you can multiply it by the unit cost and the number of days in a month; you get the monthly cost.

How to use the appliance wattage calculator

To use the calculator for appliance electricity cost:

  1. Add an appliance from the list using the add button.
  2. Enter the power rating for the added appliance.
  3. Insert the quantity of the said appliance.
  4. Fill in the runtime per day of the appliance.
  5. Repeat the steps from 1 to 4 for different appliances.
  6. Enter the unit cost (per kWh) for the electricity.
  7. As you add more devices and their details, the appliance wattage calculator will update the cost and net consumption.

💡 If you use the advanced mode of the calculator, it will show you the daily power consumption of each appliance type, the total daily power consumption, and the daily cost.

Example: Using the appliance wattage calculator for electricity consumption of appliances

Now that you know how to calculate the appliance wattage! Calculate the electricity consumption of appliances and cost for a house with 4 ceiling fans and 5 LED bulbs. The runtime for fans and bulbs are 8 and 6 hours, respectively. Take power rating for fans as 60 W and bulbs as 8 W.

To find the household appliance wattage:

  1. Add fan from the list using the add button.
  2. Enter the power rating for the fan as 60 W.
  3. Insert the quantity of the fan as 4.
  4. Fill in the fan's runtime per day as 8 hours.
  5. Add LED bulb from the list using the add button.
  6. Enter the power rating for the LED bulb as 8 W.
  7. Insert the quantity of the LED bulb as 5.
  8. Fill in the runtime of the LED bulb as 6 hours.
  9. Enter the unit cost (per kWh) for the electricity as 0.12 $/kWh.
  10. The electricity usage calculator will return:
    • Monthly electricity consumption as 64.8 kWh; and
    • Monthly cost as $7.78.


How do I estimate my monthly electricity consumption?

To estimate your monthly electricity consumption:

  1. Find the wattage rating for all the devices you use.
  2. Multiply the wattage ratings with usage hours to get individual device consumptions.
  3. Add all the device consumptions.
  4. Multiply the sum with the number of days in a month to obtain the monthly electricity consumption.

How do I calculate my monthly electricity bill?

To estimate your monthly electricity bill:

  1. Find the daily electricity consumption by adding all the individual contributions.
  2. Multiply the daily electricity consumption with the number of days in a month.
  3. Multiply the product with the unit electricity cost.
  4. Add the taxes to the product to obtain your monthly electricity bill.

How much energy does my water heater use?

The water heater would consume ~4 kWh per day. A water heater of average size has a rated wattage value of about 4000 watts. Considering a 4000 W heater that runs for about 1 hour a day, the energy consumed per day is:

Energy = 4000 x 1 / 1000 = 4 kWh.

How much energy does my ceiling fan use?

The fan would consume ~0.6 kWh per day. A ceiling fan has a rated wattage value between 55 to 100 watts. Considering a 75 W fan runs for about 8 hours per day, the energy consumed per day is:

Energy = 75 x 8 / 1000 = 0.6 kWh.

Rahul Dhari
Use this calculator to estimate your household electricity consumption. If you are looking for a simplified version, please use this electricity cost calculator. You can begin by adding the appliances you own.
Energy consumption (monthly)
Unit cost
$ /
Monthly cost (without taxes)
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