What Size Inverter Do I Need? Complete Guide

Sometimes the power outages in some areas, and it happens commonly in other areas.

But you need a permanent solution to continue running the house’s appliances.

Some people prefer generators, but most of them stick to inverters as they are more friendly to electricity and work differently.

Before you buy an inverter, you need to know what size inverter you need, which is a serious and common problem as you are not an electrician.

We have resolved all your issues regarding buying inverters in this article. Follow the article till the end, and you will know what size inverter you need.

What is an Inverter?

An inverter is an electrical device connected to a 12-volt DC battery that supplies power to the inverter.

Then it converts into a 12-volt AC power provided to the house. You can connect the output to any device you want to run in your house.

Moreover, you can connect all the appliances in your house at the same time.

It will automatically supply power when the power outages. To sum up, the device converts direct current to the alternating current used to run the house appliances.

Read More: Best Pure Sine Wave Inverters

What is the difference between an Inverter and a Generator?

inverter vs generator


The experts refer to the inverter as an inverter generator and a generator as a conventional generator. The conventional generator produces a conventional current, while the inverter generator works entirely differently.

Inventor generator converts high voltage power to direct current and then to stable alternating current. This is the main difference that is based on functionality and performance.

Besides, there are small differences like capacity, noise, portability, quality of the power produced, maximum power output, and efficiency.

Read More: Best 3500 Watt Inverter Generator

How much power do you need for an Inverter?

Before you buy an inverter, you need to know what size of inverter you need.

How would you know what size of the inverter is required?

To solve this mystery, you need to know how much power your house is utilizing.

Once you know this answer, you will be able to know the rest. You need to know every device or appliance that you want to connect with the inverter.

Once you figure that out, calculate all total power by adding each appliance’s power.

Usually, the power is mentioned on the device or their box. Most of the time, power is mentioned in watts; you can simply convert it if power is in amps. Multiply 120 by the number of amps, and you will get an answer in watts.

Now you can head toward the next step, where you will know what size of inverter you need for your house.

Read More: Best 3000 Watt Inverter Generators

What size of Inverter do you need?

Depending upon your requirements, your inverter size may vary greatly.

Once you know the requirement of power your house needs, you can easily find an inverter’s size by following these simple steps.

Step 1: You will have to require some estimates of appliances you want to supply power through the inverter. Another essential factor is how many hours you need to supply power. Both of the answers are necessary to calculate the total required supply from the inverter to the house.

For example, we have these appliances that we need to run when there is a power outage.

  1. Mobile Phone – 50 Watts
  2. Hairdryer – 1,000 Watts
  3. Light Bulb – 100 Watts
  4. Portable Heater – 2000 Watt

The total wattage required to run these appliances is 2650 watts. Keep in mind these are rough ideas and may vary. The sole purpose is to calculate the power. The hairdryer and heater require almost twice the power to start. So, adding the start-up power, our total will be 5,150 watts. Now see the difference between running and starting power needed to supply through the inverter.

Step 2:

Now, you know the total current required to run all the appliances is 5,150 watts, not 2650 watts. So, you will buy an inverter that can supply at least 5,150 watts of power.

Step 3:

You need to know how long these 2650 watts will run. Let’s suppose 10 hours is the maximum time to run these appliances at the same time. Usually, hair dryers do not run continuously for 10 hours unless you own a parlor, but we have to consider calculating the exact power. Narrow down the run time by 50% of the 10 hours, which will be 5 hours. All the batteries are rated in dc amps, so we need to convert ac watts to dc amps hours.

  • Further, we need to convert ac watts to dc amps per hour by dividing the watts by DC voltage. The DC voltage could be either 12v or 24v but let’s consider commonly used 12votlts.
  • 2650 ac watts / 12 dc volts = 220.88 dc amps per hour.
  • Now 220.88 dc amps is the power required per hour.
  • To calculate the total power required for the whole day, we have to multiply this per hour power on dc amps by the number of hours per day that are 5 hours.
  • 220.88 dc amps per hour X 5 hours = 1,104.4 dc amps.

There might be power loss during the inverting process by the inverter that can be around 5%. Add the loss with the results 1,104.4 dc amps + (1104.4 X 5%) = 1069.62 dc amps.

Step 4:

Now, you have a complete idea of how much power is required, so you can easily select the inverter that best suits your house requirement.

Standard Inverters to run a Specific Appliance

300-Watt Inverter LCD Television and Lightbulb
400-Watt Inverter Mini Fridge
500-Watt Inverter Laptop, Laser Printer, Lightbulb, and LCD Television
750-Watt Inverter Mini Fridge and LCD Television
1000-Watt Inverter Hairdryer

Final Verdict

Make sure you follow all the precautions needed for your safety. Don’t risk yourself while installing, and consult a professional electrician. Consider an inverter with more power than your house actually needs; otherwise, you may ruin a newly bought inverter. For that, it is necessary to calculate the current supplied to your house. You can calculate by the above method or simply use calculators designed for these purposes.

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