For those of you out there wanting to save electricity one of the formulas you will need to know is the formula to calculate your kWh usage or elecricity usage. This way you know what each device in your home is using. So you know where you can cut your costs in your home. The information found here will teach you what is a kilowatt hour, how to calculate kWh, convert watts to kWh, and more!
First of all kWh stands for Kilowatt Hours. This is usually what you will see on your electricity bill or electricity statement when you receive it. The electric comany knows how much electricity you are using by reading your kWh meter. You will also have the electricity cost per kWh listed on your electric bill so you know what each kWh is costing you.
A kilowatt hour is a measurment of how many kilowatts are used in a hour. Most electrical devices will have printed on them how many watts they are using, which it takes 1000 watts to equal 1 kilowatt. So a 1000 watt microwave oven running for 1 hour will use 1 kWh.
Watts is a measurement of how much electricity that electrical device uses constantly, where kilowatt hours is how many watts that electrical device has accumulated over time. For example a 60w incandescent light bulb in your closet will use 60 watts everytime it is turned on. But if it is turned on an hour a day while you pick out your clothes that’s 30 hours that light has been on that month. That’s 1,800 watt hours or 1.8 kilowatt hours. Continue reading this information on how to calculate kWh to get the formula used to calculate your kWh usage
But for those of you that are wanting to calculate what each electrical device in your home is using then you will need to use this formula to calculate the kWh usage in your home:
( Watt Usage * Hours/Day * Days/Mo. ) / 1000 = Kilowatt Hours used that month
So for an example we have a normal incandescent light bulb that uses 60w, that we have on 16 hours every day of the month. So I can calculate how many kWh this incandescent light bulb is using every month by using this formula:
60w * 16 hours/day * 30.5 days/mo / 1000 = 29.28 kWh per month
After you know how many kilawatt hours a device is using you can multiply this kWh by the cost per kWh that is stated on your electric bill:
kWh * Cost/kWh = Cost per month
So using the 60w incandescent light bulb example, which was using 29.28 kWh/mo.:
29.28 kWh * $0.10/kWh = $2.928/mo.
So a single 60w incandescent light bulb will cost you $2.93/mo.
NOTE: This is based on $0.10/kWh and also I have the amount of days per month 30.5, I figured this way I don’t have to figure out if this month is 30 days or 31 days.
You have to know how many watts a device is using before you can use any of the formulas found in the information above. Most devices will have the wattage printed on the electrical device somewhere. If your electrical device does not have the wattage printed on it but it does have amperage printed on it, please look at Volt Amp Watt Convert to learn how to convert amps to watts. If your electrical device does not have amperage or wattage printed on it, then you will have to learn How to Measure Amperage with a Multimeter.
Thank you for reading this information on How to Calculate kWh on Go Green in Your Home. Go Green in Your Home hopes this information has helped you calculate each of your electrical devices kWh usage so you know how much electricity you are using. For more tips on how to save electricity or save the environment continue reading through Go Green in Your Home!
October 16th, 2009 at 10:46 pm
Hello from Russia!
Can I quote a post in your blog with the link to you?
October 22nd, 2009 at 10:12 am
Yes, you can do that, as long as you link back to this site. Hope you find our information very helpful and come back to find more and more information on how to go green and save money!
November 17th, 2009 at 6:44 pm
Hello,
What kind of device (KW or KVA)you recommend for supply 14,025 Kwh/month?
Thanks
Miami,FL
February 10th, 2010 at 5:35 am
8.5KW*5Hrs/day how much KWH unit?
February 10th, 2010 at 6:12 pm
Wow, 8.5KW?? That’s 8,500 watts? Well if that figure is correct, and it is on for 5 hours a day, that would be 8,500 x 5 = 42,500watt hours, which then you would convert this to KWH, 42,500 / 1,000 = 42.5KWH / day the device is in use.. at $0.10/KWH that would cost you, 42.5KWH x $0.10 = $4.25/day or $4.25 x 365.25 days = $1,552.31/year!
May 28th, 2010 at 11:47 pm
I consume an average of 6 kWh per day. A solar panel supplier is offering me panels of 46 watts and 34 watts each. How many panels do I need to supply the consumption I have and be sure I will not run out of electricity at any time?
June 30th, 2010 at 9:39 pm
This really depends.. the kWh per day doesn’t really matter too much when you are trying to calculate how much power you need. The other variable you will need to know is the maximum you consume at once. Say an A/C unit will draw 3,500 watts at a time, if that and your electric oven ( 3,000 watts ) turn on at the same time, that’s a current draw of 6,500 watts at one time. So you would need enough solar panels to supply 6,500 watts at once ( 6,500 watts usage / 46 watt solar panel = 141.304347826 ), so you would need 142 solar panels that produce 46 watts.. which is ridiculous. So you need a way to store this power, when you aren’t using it. To store the power you would need a charge controller and a battery bank. Well 6 kWh /day would be 182.625 kWh / month. I’ll give you a little more just incase. So 7 kWh /day will give you 213.0625 kWh / month. ( 7 x 365.25 / 12 = 213.0625 )… Now a single 46 watt solar panel can produce ( 46 watt x 14 hrs of sunlight x 365.25 days a year / 12 months / 1,000 = 19.60175 kWh / month ) you need to get 213.0625 kWh just to be safe, so 213.0625 kWh needed / 19.60175 kWh per panel = 10.869565217.. so 10 – 11 solar panels would work fine for you. You can get some solar panels online that can produce more watts so you don’t need as many. But sometimes a lot of smaller panels might be cheaper.