So you are wanting to convert volts, amps, and watts. This is a rather simple conversion you can do with a calculator, you don’t need any special devices, but there are some devices out there that will convert volts, amps, and watts for you. Every electrical device in your home should have it’s voltage and amperage or voltage and watts printed on it. If not you will need to use a multimeter to find the voltage and amperage or voltage and watts.
But for those electrical devices in your home that have volts and amps or volts and watts printed you can convert amps to watts or convert watts to amps depending on what measurement you want.
If your electrical device in your home has the voltage and amperage printed on it you can convert this to watts by multiplying the voltage and amperage.
Voltage * Amperage = Wattage
So if you have a laptop that has 20 volt 4.5 amp printed on the power supply then that power supply is capable of using 90 watts.
20 volts * 4.5 amps = 90 watts
Pretty simple to convert volts and amps to watts. For those of your electrical devices that have voltage and wattage printed on the power supply, you can convert volts and watts to amps simply by dividing the wattage by the voltage.
Wattage / Voltage = Amperage
Now if your laptop’s power supply has 20 volt 90 watts printed on it, then you can take the watts and divide them by the voltage to get the amperage.
90 watts / 20 volts = 4.5 amps
Now if your electrical device does not show the voltage, amperage, or wattage you can use a multimeter to measure the voltage and amperage, then convert this to wattage.
Thank you for reading this tutorial on how to convert amps, volts, and watts. If you have any questions please leave a comment on this conversion formula and Go Green in Your Home will try to respond back as soon as possible. For more tips on saving electricity or ways to go green continue reading through Go Green in Your Home! Have a great day!
September 25th, 2009 at 8:00 AM
[...] Go Green in Your Home « Volt Amp Watt Convert [...]
July 30th, 2010 at 7:09 PM
Sorry, I still need help. I want to go to solar backup. How do I convert my current average of 1550 kwh to amps so I can choose the correct ampage on a solar panel.
August 8th, 2010 at 11:06 AM
Well most solar panels I’ve seen go by wattage, not amperage. Is this 1550kWh per year? per month? per day? Are you going to run directly from solar panels or are you going to have batteries charging as well? These are things that need to be know to be able to figure out what type of solar panels are needed, and how many.
December 28th, 2010 at 5:25 PM
how much would it cost to run 90 amp electric heater for 24 hour @12 cents a kwat hr thank you
January 2nd, 2011 at 2:51 AM
What is the voltage? I need the voltage of the 90 amps to convert it to watts.
February 15th, 2011 at 4:38 PM
I have 36,000 sq. meters of area that can produce 10 watts per sq. meter for min of 8 hours a day.
how much savings based at 11 cents a kwh.
could you help me with some KWH per day costs, savings, etc.
February 15th, 2011 at 7:50 PM
36,000 sq. meters producing 10 watts each sq meter = 36,000 x 10 = 360,000 watts
(360,000 watts x (8 hrs each day x 365.25 days a year)) / 1,000 = 1,051,920 kwh per year ($115,711.20/year)
1,051,920 kwh / 12 = 87,660kwh per month ($9,642.60/mo. based on $0.11 / kwh)
hope this helps, let me know if you need any other help.
March 11th, 2011 at 12:09 PM
Hi, I have an appliance in my shop that is 7.5Kva. Can you tell how to measure the power consumption per hour for this,thanks
March 20th, 2011 at 12:18 AM
Anita,
I would need the PF (Power Factor) to be able to do any calculations for you. The standard/average is a PF of 60% or 0.60, but this is not always the case. Depends on the generator, transformer, etc. whatever your appliance is. You may be able to find this info on the unit’s power ratings. If you can get me that information I’d be happy to help you out. Thanks and have a great day!
April 12th, 2011 at 11:30 AM
LOTS OF GREAT INFORMATION I NEED SOME HELP I LIVE IN A MOTORHOME AND TRAVEL ALL OVER I HAVE SOLAR PANNELS ON MY ROOF AND FOUR 6 VOLT BATTERIES IN STORAGE. MY QUESTION IS MY POWER METER READS IN AMPS. AND DURNING A NORMAL DAY I AM USING 5 TO 6 AMPS AS A CONTANT. IF I TURN ON THE WATER HEATER OR THE AC IT WILL JUMP TO15 TO 17 AMPS. WHAT I WANT TO KNOW IS HOW DO I CONVERT AMPS TO WATTS SO I CAN GET A FAIR IDEA OF HOW MUCH POWER I AM USING AND WHAT IT COSTS IF I HAVE TO BUY IT FROM A SOURCE AT SAY 12 CENTS PER KWH
THANKS FOR YOUR HELP
KENNY
May 19th, 2011 at 7:52 PM
Kenny,
This depends on if the amp meter is running after the voltage is 120VAC or if its before the inverter on the 6VDC battery side. Im going to assume it is after the inverter on the 120VAC side.
5amp x 120V = 600watts
6amp x 120V = 720watts
So your constant pull is 600 – 720watts
With your AC or water heater on you are pulling
15amp x 120v = 1,800watts
17amp x 120v = 2,040watts
So you are pulling around 1,800 – 2,040watts when AC or water heater is running.
Hard for me to figure out the ac or water heater for cost as I don’t know how many hours they are running. As for the constant, I can help you there as it is 24 hours everyday.
I’ll use the 720watts for this calculation.
720watts x 24hours x 365.25days / 1000watts / 12months x $0.12 = $63.12 plus some companies may tack on an extra $10-$30 for “delivery” basically a charge to use their electric lines.
As for the water heater and AC you can use this formula to figure out how much the cost is per month instead of the formula above:
I’ll use the 17amp but yet subtracting the constant since we have that calculated already.
1,320watts x plug in hours per day here x 365.25days / 1000watts / 12months x $0.12 = cost per month with ac/water heater running, now add that to the constant $63.12
Hope that answers your question, have a great day and remember to visit often!
May 29th, 2011 at 10:40 PM
hello there i am loking for buying a new power supply for my computer, and i got a little question about it
it says on the information, that the power supply can generate up to 50 amps of power, my question is, i live in an appartement and my electric box uses fuses, i got a 20 amp fuse and a 25 fuse, my question is, does a power supply convert volts into amp or smthing or will it take raw amp and make my buse break all the time?
June 9th, 2011 at 7:53 PM
Jean-Marc,
A computer power supply pulling 50amps!?!? That can’t be correct. 120V x 50amps = 6,000watts.. Most likely the 50amps is on the 12v side of the power supply 12v x 50a = 600 watts. Which seems more likely. The power supply will probably say 600watts on it. With a 600watt pull that would be 600watt / 120volt = 5amp. So your computer power supply will be pulling 5amp.
November 4th, 2011 at 12:36 PM
hello..if load is 500 watt,monthly consumption is 200 units ,so how can i calculate the kwh?
November 6th, 2011 at 10:42 AM
Ram,
Sorry I don’t understand your question. Not sure what 200 units means. 200 hours?
January 22nd, 2012 at 1:16 AM
How many average 2,000 Sq Ft homes in the northeast would a 76 KW generator be able to power? Assume no central air, and oil fired furnaces (no electric heat).
Thank you.
January 23rd, 2012 at 11:49 PM
Tom,
Is this a 76kw wind generator? Gas, solar, etc.? This will help me understand how long the generator will be running each day. Thanks!
January 31st, 2012 at 5:04 AM
pls i need help on connecting my solar panel with an inverte and batteries can u help me with diagram on how to connect it..pls i will be grateful . thanks
January 31st, 2012 at 11:38 PM
Isaac,
You need a charge controller as well. I don’t have a diagram handy, but you want your positive (+) side of the solar panels connected to the positive (+) of the charge controller input, do the same with the negative (-). Now connect the charge controller battery side or output to your battery in the same manner, positive (+) to positive (+) and same with the negative (-). Then the battery gets connected to the inverter the same way. Then the inverter can have devices plugged into it directly, or you can wire it to your circuit breaker box to power a certain set of devices/outlets, or you can have it power entire home.
If you are connecting the inverter to the breaker box, install a separate breaker for the inverter with it’s own outlet. This way you can switch from power company to solar, or solar to power company. If used as a backup, you can turn off mains from power company then turn on breaker from inverter so your electricity doesn’t get passed through the lines to people working on the power lines.
May 8th, 2012 at 1:41 PM
What is the cost savings. I power washed the coils on my AHUs.I dropped 5 amps off of each phase.480volt unit. What is my cost savings over the year if they run for 12 hours each day 365 days a year. My cost is .11cent per klh
May 10th, 2012 at 8:00 PM
Brian V,
If you dropped 5amp off of each phase that’s
480volt x 5amp = 2,400watts saved
2,400watts x 12 hrs x 365.25days / 1,000 = 10,519.2kWH per year saved
10,519.2kWh x $0.11 = $1,157.112 saved per year
May 19th, 2012 at 1:52 PM
Need help I’ve got 6 – 11watts lights 230volts. that I want to run off a 12volt battery 110ah how long will it last for ??
May 20th, 2012 at 10:20 PM
Rich,
The lights would not operate properly if you connected them to a 12VDC battery. You would need to use an inverter to step up the voltage and to create AC power. A 12V battery is DC, where the lights are 230V AC. You can buy an inverter to go from 12VDC to 230VAC and then be able to run the lights. But buying an inverter just to run some lights I think is silly. I would recommend buying 12VDC lights to connect to the battery. You could find many different lights to run on 12VDC. Even car headlights are 12VDC. Depending on what kind of lighting you need. You can search on amazon.com and find all kinds of 12VDC lights.
May 21st, 2012 at 10:47 AM
Hi, thanks for replying
Sorry yes I’ve got a 500w inverter I’ll be using. the thing is thier main lights in a shop an also I’ll be having more solar panels to my 30a charge controller an adding more battery’s, so I can run a small LCD screen (for CCTV ) an a freezer, aswell as lights , I’m starting with 6 lights, how long would they last for? I’m wanting to run 6 11w 220v for 9hours on a 110ah battery is that possible ? Cheers
May 29th, 2012 at 5:44 AM
Thank you for a comprehensive coverage of the subject. I still have a question though. Dividing watts by volts to calculate current drawn (in amps) is fine for DC but in the back of my mind there is a question about an adjustment needed in the case of AC. What would the current draw be for a device of 3000 watts at 220v AC?
I would be so glad to have your response.
Garth Blain.
June 16th, 2012 at 10:53 AM
Garth Blain,
Converting watts to amps or amps to watts is the same for AC power and DC power.
December 25th, 2012 at 8:47 PM
Hello, We live off the grid and have a 48v solar system with back up batteries. In the evening when the sun has set and we look at our inverters it says the batteries are at 50 volts (which is fully charged). My question is how can I translate that into available watt hours? Meaning how much electricity can I use before I run out of electricity? Our system will stop running, to protect the batteries, when the volts drop down to 45.
Thank you, Kris
January 22nd, 2013 at 9:41 PM
Kris
This depends on what size batteries you have and how many. It also depends on how much you’re using on average.