How to Calculate Electric Bill
Knowing how to calculate electricity cost goes far beyond learning how to read your electric meter. While using the meter is a good step towards saving on electricity costs, having an understanding of just how much each of your appliances is costing you to run is also important.
Once you know this, it is just a matter of learning how to calculate electricity cost for each appliance. Though doing so is not always easy, it can be managed and done by following some simple steps. Success in these efforts will grant you a better idea of what is costing you within your home and should help you to reduce the cost of electricity each month.
Step 1: Check the Appliance
To begin calculating electricity cost, examine your appliances. You’ll want to look at the back or bottom of each to see if you can spot an energy unit listing. In the best-case scenario, your appliance will have the wattage listed there. Sometimes the listing uses amperes instead, which is fine but will require an extra step to calculating cost.
Step 2: Calculating with wattage
In the event the wattage was listed on your appliance, you are in luck! Simply divide the wattage number by 1000, which is the same as moving the decimal left three spaces. This will give you the appliance’s kilowatt hours(kWh). When you have this number, you can either go online or check your bill to find your electric company’s rates. Multiply the appliance’s kWh by the company’s rate, and you will know how much each appliance costs to run, per hour.
Step 3: Calculating with amperes
If the electrical usage is listed with an A after it, that denotes amperes. To determine the cost of electricity for that appliance, you’ll need to convert the amperes to wattage. This is done by multiplying the amps by the voltage used (usually 120, sometimes 240), and then divide that number by 1000 to determine the kWh. From there it works the same way as before, meaning that you’ll need to look up the rates online and with a quick calculation, you will have the cost of running the appliance.
Using a Monitor
In the event you have an electrical usage monitor, like Kill-A-Watt, you do not have to know how to calculate electricity costs. This device assesses the efficiency of appliances and will tell you the kilowatt-hours of your devices. With that information, you can multiply the value by the rates charged per kilowatt hour by your energy provider and determine the cost of your devices.
Example
To reinforce the steps above, the following is an example that is meant to demonstrate how to go about calculating electricity costs. Consider a kitchen blender that is labelled as using 1500 watts. You’ll next want to calculate the kilowatt hours of the appliance, so divide 1500 watts by 1000.
1500/1000 = 1.5 kWh
From there, you’ll want to take your electricity rate and multiply it by the kWh amount. For this example, imagine your rate is 11.7 cents/kWh.
1.5 kWh x 11.7 cents/kWH = 17.55 cents
And that is the cost of running your kitchen blender per hour. Now instead of beginning with wattage units, imagine that your blender was instead listed in amperes. For this example, your blender amperes are 15. What you’re going to do is multiply the 15 amperes by the voltage of 120.
15 amperes x 120 volts = 1800 watts
Once you have this answer you can divide by 1000 and then multiply by the rate of 11.7 cents/kWh to determine the cost.
1800 watts / 1000 = 1.8 kWh
1.8 kWh x 11.7 cents/kWh = 21.06 cents
In this example, the cost of the kitchen blender per hour is 21.06 cents.
Knowing how to calculate electricity costs can be extremely helpful in deciding how and when to use your appliances. For example, if your electric company charges more for certain hours of the day, you can choose not to use high kWh appliances during those hours. Once you know how to calculate the electricity cost of an appliance, you can also be a more informed consumer, because you’ll know what all the numbers on the appliances mean, in terms of dollars and cents.
How much is your energy bill?
Now that you’ve known how to convert amperes to watts and watts to kilo-watts hour and you’ve also understood how to the electricity usage of a certain electrical appliance, the next step is to calculate your total electricity charges.
Calculating your total electric bill is rather easy as you only need to sum-up the energy usage in kWh of all your appliances and then multiply them by the electricity rate. For example;
If you have a 150W T.V that you watch for 5 hours every day, the T.V will be consuming 750 watt-hoar per day (150 X5). As demonstrated earlier, to convert it to kWh, you’ll have to divide it by 1000 to get 0.75kWh per day. If we take an electricity rate of 12 cents per kwh, the charges for electricity usage per day for this device will be (0.75X 0.12 = 0.09). This means that the TV accounts for $2.7 per month (0.09 X 30), that is if you use the TV every day for the same number of hours for 30 days. Do the same for all the appliances and then sum them up to come up with the monthly electric bill.
As you can see, this involves a lot of calculations and number crunching if you were to do it for every appliance, bulbs, and all the other devices. So, why don’t you go the easier way – use of technology.
Tech Tools for Determination of Electricity Bill
There are several technological tools that you can use to calculate your electricity bill. Companies such as; Sense, Neurio, and Curb have created gadgets that can link to your house’s main electric panel and identify the unique electrical signal of the devices in your home. Each of the products from the three companies is unique and works differently but they all show the energy usage and its analysis through a web product or an app.
