A hot summer’s day can be hell without air con. Life just becomes unpleasant as you become sluggish and unproductive in the heat. Fortunately, there’s plenty of choice available to keep you cool when temperatures soar. You can easily install window or portable machines in your home, office, or in vehicles like boats and RVs. The only thing you need to consider is the electricity and power consumption.
Below we will discuss and test air conditioner wattage, explain how to work it out for yourself, and calculate the total electricity required.
How Many Watts is an Air Conditioner?
The average air conditioner uses between 500 and 3000 watts.
The exact number depends on the size and model of your air conditioner. The difference in these appliances is huge which is why there is such a large power variation. For example, a smaller 5,000 BTU air conditioner uses less than 500W, while large 25,000 BTU air conditioners use over 2000W!
Air con size is measured in BTU. This is a rating for how much energy it takes to heat or cool a pound of water. The higher the BTU number the higher the power consumption. An air conditioner with a higher BTU is bigger and able to cool larger rooms.
How to Find Out Your Air Conditioner Wattage
There’s 3 ways you can work out the wattage of an air conditioner.
- Check Product Specification
The quickest way is to look at the air conditioner’s specifications. The watts (W) is usually written on a sticker on the base of the appliance. If not, you can check the user manual or the manufacturer’s website for technical details.
- Use a Wattmeter
A wattmeter is brilliant for getting a live wattage reading and tracking total energy usage of any appliance. You can simply plug it into your air conditioner to get instant information.
I used one to test 10,000BTU air conditioner which gave a live reading of 1013W.
- Wattage Formula or Calculator
If you know the amperage and voltage of your air conditioner you can use this to find the maximum watt rating. Simply use the formula Amps x Volts = Watts. Or you can head over to the ‘Watt Calculator’ to work this out.
Air Conditioner Wattage Examples
Let’s take a look at specific examples of how many watts an air conditioner draws. Below is a collection of modern air conditioners with their listed power ratings.
| Air Conditioner Model | Power Rating (Watts) |
| Keystone 25,000 BTU | 2427 |
| Keystone 12,000 BTU | 1000 |
| Keystone 10,000 BTU | 833 |
| Keystone 8,000 BTU | 666 |
| Keystone 6,000 BTU | 490 |
| Keystone 5,000 BTU | 410 |
| LG 12,000 BTU | 990 |
| LG 15,000 BTU | 1260 |
| SereneLife 12,000 BTU | 1150 |
| SereneLife 10,000 BTU | 1150 |
| SereneLife 8,000 BTU | 900 |
As you can see, the power ratings vary between different air conditioners. So you should take the time to check your own appliance.
How Much Electricity Does an Air Conditioner Use?
You can use air conditioner wattage to work out how much electricity it uses. Plus this can be useful in understanding how much it costs to run your air conditioner.
A watt (W) is a measurement of power at a single point in time. A watt-hour (Wh) is the total amount of electricity used in an hour. For example, an air conditioner drawing 1000W would use 1000Wh when running for an hour.
Happily, electricity bills are recorded in kilowatt-hours (kWh). A kilowatt is simply 1000 watts. So a 1000W air conditioner running for 1 hour uses 1kWh.
Let’s say you use your 12,000 BTU air con for 5 hours a day. This means an air conditioner uses about 5000Wh or 5kWh electricity a day. That’s 150kWh a month and 1825kWh a year.
That’s a rough electricity cost of $0.75 a day or $273.75 a year to run a 12,000 BTU air con for 5 hours every day.
Of course, the exact number will change based on your air con size and usage habits. For example, you might only run it in the summer months rather than every day of the year.
Using an Air Conditioner Off-Grid
If you’re planning to use your air conditioner in an off-grid situation like a power outage, RV, boat, semi-truck, or similar, the information above is important. It enables you to pick the correct power products and know how long you can run your air con.
You can either use a power inverter, portable power station, or generator to generate AC electricity.
To make sure everything runs smoothly you should check two things on this equipment – wattage capacity and total energy capacity.
Your power source, like an inverter, should have a wattage capacity of at least 20% more than your air conditioner. This ensures it will be able to deliver enough power as they are never 100% efficient.
Secondly, you need to ensure your energy source, like a battery, has enough energy to run the air conditioner for the required amount of time. For example, a small 5000 BTU machine will use about 400Wh electricity for each hour. This is the equivalent to 33.33Ah on a 12V battery.
How Many Watts Does an Air Conditioner Use Summary
I hope you now have a clear understanding of how many watts an air conditioner uses.
Keeping cool in the summer is no joke, and your air con uses plenty of electricity. The higher the BTU the more power it draws. In addition, you will be running the appliance for long periods so you’ll notice a spike in your electricity usage. If you’re worried about utility bills and energy usage then switch to a smaller unit. Plus when running off-grid ensure your power supply can cope with the demands of running for long periods.
