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Understanding Portable AC Wattage Consumption and Its Impact

Josh Mitchell

Written By

Josh Mitchell

Expert Reviewed By

Holly Curell

Last Updated On

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I've worked with all kinds of portable AC, and there's a big difference in the cooling capacity, coverage, and power draw.

They don't have the power draw of large, central air conditioners, but the wattage can be surprisingly high. So, exactly how many watts does a portable AC use?

In this guide, I'll explain how many watts your portable AC uses, why it matters, and how you can save hundreds of dollars with an energy-efficient unit.

Key Takeaways

  • A portable AC can use anywhere between 400W - 2000W. Portable ACs come in small to large sizes.
  • The energy consumption of a portable AC depends upon its cooling capacity, energy efficiency, ambient temperature, the temperature settings and the size of the covered area that needs cooling.
  • The energy consumption can help determine the running costs and the electrical circuit requirements for your portable AC.

How Many Watts Does Your Portable Air Conditioner Use?

On average, portable air conditioners use 500-1500 watts of electricity.

However, the energy consumption of every portable air conditioning system is slightly different.
How many watts does a portable AC use

Generally, the larger the portable air conditioner, the higher the energy consumption.

  • Small/compact portable air conditioners will use 500-800 watts. These are great for short-term cooling in a single room, office, or smaller spaces.
  • Medium-sized portable air conditioners will use 900-1200 watts. I recommend using these in larger living spaces.
  • Large portable air conditioners typically use 1300-1500 watts. These are more effective at managing the temperature in large spaces or whole apartments.

You can also get industrial-grade portable air conditioners for large, open spaces (like garages, basements, or open-plan homes).

These can draw more energy, often over 1500 watts.

TL;DR: The power draw of a portable air conditioner depends upon its size and the square footage area it is designed to cool.

Portable Air Conditioners Vs Other Air Conditioning Systems

Portable air conditioners tend to have a lower wattage than other AC units, although it can vary depending on the size, make, and model.

A window air conditioner can also be low wattage but provides less flexibility.

Central air conditioner systems draw the most watts because they need more energy to provide cooling across your home.

Mini split air conditioners offer a halfway house between central air conditioners and portable air conditioning systems/window air conditioner systems.

If you need whole-home cooling, I recommend a mini-split system over a central air conditioning system as they are more energy efficient.

Type of air conditioning system

Average Wattage Range

Portable air conditioner

500-1500 watts

Window air conditioner

500-1500 watts

Central air conditioner

3000-5000 watts

Ductless mini split air conditioners

900-2000 watts

TL;DR: Due to the lower cooling ability, portable ACs often have a fairly low wattage rating.

How Size Impacts Portable Air Conditioner Wattage

The physical size of your air conditioning system doesn’t matter - it’s all about the cooling output.

The output or capacity of your air conditioner is measured in British Thermal Units (BTUs) and shows you how much cooling it can provide in your home.[1]

The higher the BTUs, the more cooling it can provide, but the greater the energy consumption.

Some other factors impact the wattage of your air conditioner, but none are as important as the relationship between BTUs and Watts.

The exact BTU-Wattage ratio varies, but the table below provides a rough guide to the wattage for different-sized portable air conditioners:



5000 BTU

417-625 W

6000 BTU

500 – 750 W

8000 BTU

667-1000 W

10000 BTU

833 – 1250 W

12000 BTU

1000 – 1500 W

15000 BTU

1250 – 1875 W

TL;DR: The singular most important metric that impacts the wattage is how many BTU the unit is rated at. Usually, portable ACs are rated at 5,000-15,000 BTU consuming anywhere between 400W-1,875W per hour.

Important Note

Watts measures the rated power a device needs to function. kWh measures how much electricity a device consume in an hour.

e.g. A 1,000W portable ac running for an hour would consume 1000 Wh or 1kWh of power. The same running for half an hour would consume 500Wh or 0.5 kWh.

Electricity utilities charge bills by kWh.

Other Factors That Impact Portable Air Conditioner Wattage

  1. 1
    Energy efficiency ratio
    Air conditioners with advanced inverter technology and Energy Star ratings will have lower energy consumption and wattage.[2]
  2. 2
    Design & build quality
    Air conditioner technology is improving year on year. Modern units are more efficient, with new compressors and internal components in the cooling system. These will draw less power to provide the same amount of cooling capacity/cool air.
  3. 3
    The lower the temperature and higher the fan speed settings, the greater the energy consumption of the portable cooling system.
  4. 4
    Room Size
    Cooling large spaces requires greater energy consumption because your air conditioner has to run longer to provide more cool air. You can maximize efficiency and cooling capacity by making sure your air conditioners are sized to meet the cooling demand - even if that means upgrading to a central air conditioning unit.

TL;DR: From efficiency rating to the thermostat setting and the room size you wish to cool, all impact how many watts the portable AC ends up consuming.

How Many Watts Do Portable ACs Use In Different Countries?

The voltage used in countries can differ, but that doesn’t necessarily mean the appliance energy consumption (watts) is different.[3]

There can be slight regional differences, but portable air conditioners will use about the same amount of watts regardless of where you use them.

The table below shows the voltage and wattage for four major countries:



Average Wattage Range for Portable ACs

United States


500 - 1,500 watts

United Kingdom


600 - 1,800 watts



600 - 1,800 watts



600 - 1,800 watts

While the watts per hour and how much power they draw stay relatively consistent, the running cost of portable air conditioners can vary because of differing electricity prices.

I recommend taking a few minutes to calculate the estimated running costs so you aren't surprised by your energy bills.

TL;DR: The wattage used by portable ACs in different countries remains the same. However, depending upon the price per unit, electricity bills can vary.

how much electricity does a portable AC use

Calculating The Wattage for Any Portable AC

There are two ways to calculate the wattage for your portable AC:

1.Using the Amps & Voltage

If you know the Amps and Volts of your portable AC, you can use this equation:

Amps x Volts = Watts per hour

If the portable AC pulls 10 amps and it’s a standard 120-volt circuit, it would be:

10 x 120 = 1200 Watts per hour - that’s how much energy it will draw.

2.Using the BTUs and Energy Efficiency Rating

If you know the BTUs (cooling capacity) and Energy Efficiency Rating (or energy efficiency ratio), you can calculate how many watts your portable AC will use with this equation:

BTU rating / Energy Efficiency Rating = Watts per hour (how much energy usage per hour)

If your portable air conditioner produces 7,500 BTUs and has an energy efficiency rating of 10, it would be:

7500 / 10 = 750 watts- that’s the electricity usage per hour

Running Costs of Various BTU ACs

Portable ACs have lower running costs than central air conditioners, but it still varies.

You can calculate the running cost of any ACs (portable ACs, window air conditioners, or a central AC system) using these figures:

  • AC Unit Watts per hour
  • Electricity cost per kilo-watt hours (kWh) - you can find this on your electric bill. The average in the US is $0.13 per kWh for domestic use.[4]

To work out the cost per hour, you can use this equation:

(wattage x kWh cost) / 1000 = Electricity cost (per hour)

Let’s assume you have a 1000 Watt portable AC, and it costs $0.13 per kWh:

(1000 x 0.13) / 1000 = $0.13 per hour to run your unit per hour.

You can then multiply it by the running time to find the daily, monthly, or annual costs.

The cost of your portable AC electricity usage per hour may vary, but the table below gives a rough guide of the energy costs for AC units based on cooling output:

Portable AC BTUs



Cost per hour (based on $0.13 per kWh)

Cost per day (based on 8-hour run time)

Average Cost per month































TL;DR: You can use simple formulas to calculate how many kWh your portable AC consumes and also the average cost to run it every month.

How The Energy Efficiency Rating Impacts Running Costs

The Energy Efficiency Rating (EER) can make a noticeable difference to the actual energy usage costs.

Your typical air conditioner will have a 6-14 EER rating, and the higher the number, the more efficient it will be.

I recommend spending slightly more on a high EER-rated unit as it will save you a lot of money on your electric bills.

The table shows the running costs for a portable AC unit with the same cooling capacity but a different EER, illustrating just how much you could save on your electric bill:

Portable AC BTUs



Cost per hour (based on $0.13 per kWh)

Cost per day (based on 8-hour run time)

Average Cost per month































TL;DR: Higher EER rating means lower power consumption which in turn means lower bills. However, units with higher EER can cost more.

How to Find The Wattage Information of Your Unit

Check the Specification Sheet

Every portable air conditioner should come with a user manual or spec sheet. There should be a technical section showing the wattage rating of the air conditioner.

Check the Air Conditioner

Most modern portable AC systems have a label printed on the back or bottom of the AC unit showing how much electricity they use.

Check the Manufacturer

If I can't find the spec sheet or printed label, I try Googling the portable AC unit model. The manufacturer will probably have published details of how much electricity it uses.

Use Watt Meter

Plug a watt meter into your outlet and portable air conditioner to see the power consumption.

I like using this method because it shows exactly how many watts air conditioners use on different settings.

Calculate The Wattage Yourself Using BTU and EER

You can calculate the wattage of the AC unit yourself using this equation:

BTU rating / Energy Efficiency Rating = Watts (energy usage)

TL;DR: There are many ways to figure out the power consumption including checking the technical spec sheet, using a watt meter, or by using simple math formulas.

Why Understanding Portable AC Wattage is Important

1. It Explains the Running Costs

Knowing how many watts your portable AC system will use allows you to estimate the power consumption costs and budget effectively to cover your electricity bills.

2. Wattage is Used for Breaker and Wire Sizing

Your wiring and breakers must support the appropriate wattage. Knowing the power consumption allows you to power it safely and prevent circuit overloads.

3. Highlights How Energy Efficient the Model Is

Knowing the energy usage of different AC models allows you to compare the energy efficiency and choose the most energy-efficient model for your home.

4. Allows You to Choose the Best Power Source

Knowing the wattage energy usage allows you to set up the right power source.

If you're not using your residential outlet, you can choose the right generator size or determine how many solar panels you need for a solar panel system.

5. Helps Optimize Portable AC Use

Knowing the wattage, energy usage, and energy efficiency lets you adjust the settings to maximize output and minimize costs.[5]

TL;DR: Wattage is used for more than just energy consumption and for billing purposes. It is also used for figuring out the electrical circuit requirements, power source requirement, and for adjusting its cooling settings for maximum efficiency.


Do Portable Air Conditioners Use More Electricity Than Fans?

Portable AC Units use more electricity than fans because they cool the air and require more watts to power the refrigerant and compressor system.

Can You Plug a Portable Air Conditioner into an Extension Cord?

It's not advisable to use extension cords with portable AC units because it can trip the breaker or lead to short-circuiting.

If you are using an extension cord, make sure it's the right size to manage the unit wattage.

Do Portable ACs Require a Dedicated Circuit?

Portable AC units don't usually require a dedicated circuit because the energy usage is low. However, for a high-wattage AC unit, it can be beneficial to have a dedicated circuit to ensure it operates optimally and doesn't overload the circuit.


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Josh Mitchell


Josh Mitchell
My name is Josh and I am obsessed with home appliances. From portable AC units to heaters and air purifiers, I enjoy testing, learning and using these devices to improve the air quality inside my family home.

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Midea U Shaped Window Air Conditioner

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