Learn How to Calculate Your Power Usage

Knowing how much electricity you consume each month is valuable information for saving energy. Every electronic in your home contributes to your overall power consumption, even when not in use. Understanding how much energy each device uses illuminates where to cut back in your home to save on your utility bill.

Our energy experts put together this step-by-step guide with easy calculations to help you gain more insights into your energy usage.

Step 1: Find the wattage of your devices

Watts measure how much electricity a device consumes. Essentially, anything that plugs into an outlet uses watts, like lightbulbs, microwaves, and computers. Most devices have a label that notes how many watts of electricity they use. If you can’t find this information on your device, you can search online using the item and model number.

Step 2: Calculate the watt-hours per day

The following equation calculates how many watt-hours (Wh) your device uses daily. When doing this calculation, think about how many hours per day you use the device you’re measuring.

Step 3: Convert watt-hours to kilowatt-hours

Your energy bill is measured in kilowatt-hours (kWh), so you’ll need to convert watt-hours (Wh) to kWh to determine how much each device costs. One kilowatt is equal to 1,000 watts. Here’s how to convert Wh to kWh:

If you aren’t able to find the wattage label on a device, you can look up the item and its model number online, contact the manufacturer, or use a wattage measuring device.

Step 4: Estimate your monthly energy usage

Now that you know how many kWh your device uses each day, you can easily estimate its monthly usage. Multiply the daily kWh amount by 30 to get a monthly average.

In our example, a 150-watt computer monitor you use for four hours daily would consume 18 kWh of electricity per month.

 Step 5: Calculate your electricity bill

The final step is to determine how much your device costs per month. For this calculation, take the device’s monthly usage in kWh and multiply it by your electricity rate. If you’re not sure what your rate is, you can look at a previous energy bill to get the amount per kWh.

Based on these calculations, your computer monitor costs about $2.16 a month, assuming you run it for four hours every day. Keep in mind that these numbers are usually going to be approximate, but it’s a good idea to have a general sense of how much you’re paying for your devices.

If $2.16 a month to run a computer monitor doesn’t seem like a lot, remember that you have numerous devices contributing to your bill simultaneously. In this example, your computer likely isn’t the culprit for an uptick in your energy costs, but something else might be. Use these calculations to figure out what’s driving up your energy bill and create a strategy to cut back on your consumption of that device.

Now that you know how to calculate your energy consumption, you can put this knowledge to use and save on your energy costs. Here are some tips from our experts on how to reduce your energy bill:

• Monitor your HVAC unit and furnace. Heating and cooling are the two largest consumers of residential energy. Decrease how often you use your HVAC unit, or consider installing a smart thermostat to automate this task.
• Lower your water heater. Your water heater accounts for around 12% of your home’s energy usage. Lower your water heater and use more cold water to lower your energy bill.
• Switch to LED lightbulbs. LED lightbulbs use 75% less energy than incandescent bulbs, so making this switch is an easy way to lower your energy consumption.
• Unplug unused electronics. Did you know devices continue to drain energy when left plugged in? This is called vampire energy, and it’s easily resolved by unplugging electronics when you’re done using them.

If you’ve run out of creative ways to lower your electricity bill and it still seems high, it might be time to switch energy plans. Choose Energy can help you compare plans and providers in your area to find a lower rate. Our free marketplace has been helping shoppers in deregulated energy markets find power solutions for over 20 years. Enter your ZIP code on this page to get started today.