How to Calculate Home Wattage Usage

A 36-inch television uses approximately 133 watts of energy.

Reducing electricity usage is becoming more common, so knowing a home's energy consumption is important. According to the Environmental Protection Agency, three-fourths of greenhouse gas emissions created by people are generated by energy consumption or the processes to create energy. A majority of electricity that is consumed is to run items such as air conditioners, heaters and appliances. Calculating a home's wattage will help to reduce the amount of energy used and reduce electricity bills.

Things You'll Need

• Calculator
• Pencil or pen
• Paper

Instructions

1. Find the wattage of each appliance and piece of electronic equipment. This information is usually on the bottom or back of an appliance. The U.S. Department of Energy and companies such as Energy Star also produce energy tables that calculate the average wattage of certain appliances.

2. 

   A vacuum cleaner also uses wattage and should be included in the home wattage usage calculation.

   Determine the number of hours the appliance is used each day by estimating when each appliance is turned on. Multiply the number of hours by the wattage.

3. Divide the number by 1,000. The result will be the appliance's energy use or daily Kilowatt-hour consumption.

4. Multiply the kWh by the number of days the appliance is used during the year to get the annual energy consumption. Multiply the annual kWh by the local utility's kWh, which can be found on your utility bill.

5. Calculate the energy consumption for each appliance and electronic equipment in the home. Add those numbers together to estimate the wattage usage for the entire house.

Tips & Warnings

• If the wattage is not listed on the appliance, estimate the wattage. Multiply the appliance's voltage by the current "draw" in amperes. The amperes are listed on the appliance.

• Estimate the number of hours a refrigerator runs by dividing the time the appliance is plugged into the wall by three.

• Appliances such as DVD players, televisions and computers draw power even when not turned on. These "phantom loads" can be stopped by unplugging the appliance when not in use. Plugging these appliances into a power strip that can be turned off will also work to reduce energy usage.

References

• Environmental Protection Agency: Emissions
• Energy Star: Purchasing and Procurement
• U.S. Department of Energy: Energy Efficiency