The No. 1 expense of every air conditioner is electricity.
There are several ways to reduce how much does it cost to run an air conditioner. The two main ones are:
- Buying an air conditioner with a high energy efficiency rating (EER, SEER, CEER ratings are valid specifications).
- Reducing the number of hours per day that you use a given air conditioner.
Note: It’s recommended to estimate how much electricity does an air conditioner use before buying a specific unit.
On average, running an air conditioner costs between $0.06 and $0.88 per hour. Let’s calculate how much does air conditioning cost per month (running 8h per day):
- Low end: $14.40/month.
- High end: $211.20/month.
This is quite a large cost interval because air conditioners range from small 5,000 BTU portable AC units to large 50,000 BTU mini-split units.
Note: Make sure to use the air conditioner cost calculator (you’ll find it further on) to estimate your electricity bill. Here’s an example of an AC running cost calculation for 24,000 BTU AC with a $0.1319 kWh price:
Obviously, a 5 zone mini split air conditioner electricity expenditure per hour is several times greater than that of a single 12×12 room AC unit.
For example, if you have a 5,000 BTU AC unit, powered by 600W, the maximum cost of running such an air conditioner is $0.08 per hour.
Every air conditioner has a unique energy-efficiency profile. To best estimate how much does it cost to run your particular air conditioner on per hourly basis, we have prepared 4 sections to help you out:
- Table with a per hour running cost of the most common air conditioners.
- Calculator. You can input power (W) and electricity costs in your area, and the calculator will calculate how much that particular air conditioner costs to run per hour.
- Formula. The mathematical background of how to calculate the electricity costs for any air conditioner.
- Per week, per month, and season calculations. Examples of how much you’ll pay for electricity if you run an air conditioner for longer periods of time.
You can also check two very useful articles that will help you understand air conditioner power consumption. These are:
- How many watts do air conditioners use here.
- How many kWh or how much electricity do air conditioners use here.
Per Hour Running Cost Of Most Common Air Conditioners
3 most common air conditioners and the most common capacities (in BTU) are:
- Portable air conditioners (5,000 BTU – 15,000 BTU).
- Window air conditioners (5,000 BTU – 20,000 BTU).
- Mini split air conditioners (12,000 BTU (1 ton) – 48,000 BTU (4 ton)).
If we presume that all these devices have an EER rating of 10 (estimate) and that the average cost of electricity in the US is $0.1319 per kWh, we can approximate the costs of running these 3 kinds of air conditioners:
How Much Electricity Cost A Portable AC Use? (Table 1)
| Portable AC Unit (BTU) | Estimated Cost Per Hour |
|---|---|
| 5,000 BTU Portable Air Conditioner | Costs $0.07 per hour |
| 8,000 BTU Portable Air Conditioner | Costs $0.11 per hour |
| 12,000 BTU Portable Air Conditioner | Costs $0.16 per hour |
| 15,000 BTU Portable Air Conditioner | Costs $0.20 per hour |
How Much Does It Cost To Run A Window Air Conditioner? (Table 2)
| Window AC Unit (BTU) | Estimated Cost Per Hour |
|---|---|
| 5,000 BTU Window Air Conditioner | Costs $0.07 per hour |
| 10,000 BTU Window Air Conditioner | Costs $0.14 per hour |
| 15,000 BTU Window Air Conditioner | Costs $0.20 per hour |
| 20,000 BTU Window Air Conditioner | Costs $0.26 per hour |
Cost Of Running Mini Split AC Unit (Table 3)
| Mini Split AC Unit (BTU) | Estimated Cost Per Hour |
|---|---|
| 12,000 BTU (1 ton) Mini Split AC | Costs $0.16 per hour |
| 24,000 BTU (2 ton) Mini Split AC | Costs $0.32 per hour |
| 36,000 BTU (3 ton) Mini Split AC | Costs $0.48 per hour |
| 48,000 BTU (4 ton) Mini Split AC | Costs $0.64 per hour |
How much does it cost to run a mini split per month? Let’s say you use the mini split for 8 hours per day at 100% output. That means:
- Running a 1-ton mini split will cost $38.4 per month.
- Running a 2-ton mini split will cost $76.80 per month.
- Running a 3-ton mini split will cost $115.20 per month.
- Running a 4-ton mini split will cost $153.60 per month.
You can check a more detailed article about how much does it cost to run a mini split per month here. As you can see, the cost of running the most common air conditioners ranges from $0.07 to $0.64 per hour. It’s quite interesting to see that running the smallest air conditioners will cost you less than $0.10 per hour.
Calculate Running Cost Of Air Conditioner (Per Hour)
Formula: How To Calculate How Much Running An Air Conditioner Per Hour Costs
In most basic terms, the formula of how much electricity expenditure we can expect from an air conditioner comes down to two things:
- Maximum power of the air conditioner (measured in W). We can find this in the specifications of every AC unit.
- Price of electricity in your area (in cost per kWh)
Kilowatt-hour is a unit for the amount of electricity. 1 kWh simply means that we can run a 1 kW (equivalent to 1000 W) electric device for 1 hour. We have to pay for that 1 kWh of electricity; the price in the US ranges from $0.095 in Louisiana to $0.3277 in Hawaii per kWh. The cost of kWh in California, for example, is about 20 cents.
Here is the formula for the per-hour cost of running an air conditioner:
CostPer Hour = PowerAir Conditioner(in W) * Electricity CostPer kWh / 1,000
A simple example would be a 10,000 BTU portable air conditioner, powered by 1000 W, in California. Here’s how you can use the formula to calculate the cost of operating the air conditioner on your own:
CostPer Hour = 1000W * $0.20 / 1,000 = $0,20 per hour
Note that this calculation is only a theoretical estimation. In practice, the air conditioner can drain less energy because it doesn’t always operate at 100%.
You can find these running costs for all electricity-power appliances quite easily. We have calculated the runnings costs for a number of different appliances including:
- How much does it cost to run a dehumidifier?
- How much does it cost to run an electric fireplace?
- How much does it cost to run an air purifier?
How Much Does AC Unit Cost Per Day, Week, Month, And Season
In the long run, it makes sense to know how much will we spend on electricity overall. Per hour calculations can help us estimate the price of electricity we spend running an air conditioner daily, weekly, and monthly. We can also assess what an overall yearly or per season bill will be for air conditioning.
The key question here is how many hours per day do you have the air conditioner turned on. During the 3-month long summer season, most households run for 8 hours per day.
Let’s again take 10,000 BTU, powered by 1,000 W, as an example. Let’s say this unit is based in California, where the price of electricity is $0.20 per kWh.
| 10,000 BTU AC Unit | Est. Cost (Per Hour) | Est. Cost (Per Day) | Est. Cost (Per Week) | Est. Cost (Per Month) | Est. Cost (Per Season) |
|---|---|---|---|---|---|
| $0.20 | $1.60 | $11.2 | $48 | $144 |
Be Aware These Are The Maximum Rates (In Practice, You Pay Less For Electricity)
With all these calculations, we have estimated that the air conditioner is running at 100% capacity. For example, 1000 W AC is always presumed to use 1000 W of energy. The bigger 5 zones mini-split system can easily draw 3000 W.
In practice, air conditioners don’t always run on 100% power. In fact, most of the time, they use less than 80% of their total capacity.
When we turn the AC unit on, it will start with 100% capacity. After a predetermined indoor temperature is obtained, the air conditioner will use energy only to maintain that temperature. For this, it will usually need less than 80% of its overall capacity. That also means that the electricity bill will be at least 20% lower.
Note: A ceiling fan can also reduce the cooling costs by as much as 30%. For that, it’s vital to choose the correct fan direction. You can read all about ceiling fan direction for summer and winter here; it’s a simple fan rotation switch from winter to summer and summer to winter that can save you more than $100 per year on cooling and heating.
The best way how to reduce your cooling electricity expenses is to invest in an energy-efficient unit. Here are some suggestions of highly energy-efficient units (several different types of AC):
- Most energy-efficient portable AC units (10+ EER).
- Most energy-efficient window AC units (11+ EER).
- Most energy-efficient mini-split air conditioners (20+ SEER).
Hope this helps everybody to reduce cooling expenses as much as possible.
So helpful
Hi.. do you think its best to turn off my Home AC when we are not in the house like everyday from 11AM to 9PM than to let it run the whole day..?
Thanks for the help
Do you have a list of kw-hr costs are for each state? Or a link to that informayion?
Hello Warren, these costs are changing quite regularly. EIA has the best and most updated list – you can check it here.
How does heating cost compare to AC cost with a mini split system? Is the cost directly related to the difference between outdoor vs indoor temp for both? I just ordered a 48,000 system with 4 indoor heads. My thoughts were that it wouldn’t have to work as hard as a a lower BTU system and therefore save on cost to run. I guess that was an incorrect assumption. Perhaps I should have gone for a 36,000 compressor. The primary reason for going with a mini-split system was more for heating than cooling. It’s a cold climate unit (Nova Scotia) where the winter temperature averages about 14 Degrees F (-10 C) Thanks.
Hello Brooke, an interesting insight. Basically, every heat pump has to exchange sufficient heat in order to warm/cool your home. Lower BTU system and higher BTU system will still have to produce the same amount of heat. Here’s how the decision process goes: smaller BTU devices are cheaper and tend to have higher energy-efficiency (SEER rating) but they have to work harder (especially if they are too small).
Generally, the heating cost is about double the AC cost. That’s because heating air up is harder than cooling it down; you will have 20 SEER rating mini splits (cooling) with 10 HSPF rating (heating). However, both processes are limited by the maximum power output of the device. Your 48,000 BTU 4-zone mini-split, for example, has 3000-4000W maximum power output. Every hour you run it at 100%, you spend 3-4 kWh. Depending on the electricity price in your area, that can be over $1/h.
Hope this helps.
It costs me as much as $700/month to run my ac in the summer. It is 30 years old and our vents are small. From what this says, I need a much more efficient ac unit.
Hello Amber, older units can be very energy-inefficient. 30-year-old units are most probably more than 50% less energy-efficient than the newest models.
Hi, Amber. I’m in Arizona and my highest monthly electric bill in the hottest month of 100 to 110 degree heat is less than $250 for our 1900 square foot house. You would benefit greatly from a modern efficient AC. Modern windows and insulation could also help if you still have the originals.
would a small 5000 BTU window unit raise your bill up another $100 down in Louisiana
Hello Jason, let’s calculate a bit. Let’s say we run a 5,000 BTU at 100% 24h/day. Max. wattage is about 500W. So you’re burning through 500W * 24h = 12 kWh per day. The average electricity cost in Louisiana is 9.53 cents per kWh. That means 12 kWh * $0.0953 kWh = $1.14. In short, if you run the 5,000 BTU unit all the time, you’re paying about $1 per day. If you run it for 100 days (3 summer months (June, July, August), for example, you would raise the electricity bill by about $100. All things considered, this is quite an inexpensive way to cool your home.
Hello, I’m currently in the process of purchasing a house and the ductless units have peaked my interest. I’m trying to the best and cost efficient way to cool/heat my home thats 4500 sq ft. Any insight would be greatly appreciated. Thank you!
Hello Brett, ductless mini splits provide the most energy-efficient cooling (with SEER ratings above 20; much more efficient than portable, window unit, and better than central air). They also provide heating in the winter (10 HSPF rating) but the efficiency is decreased at extremely low temperatures. The most efficient cooling/heating is the mini split with the furnace combo. The furnace kicks in at extremely low temperatures in the winter. For some suggestions, you can check out the best mini split units currently on the market here.
A very educational site indeed as electric costs are inflating too.
I use an outdoor unit when the heat is hot inside, eg., about every 2 hours I run it for 20 minutes. Yesterday it ran 12 times so about 4 hours total.
My question relates to “Cost Of Running AC Per 1 Hour:”
Is this a constant hour run?
Thank you and blessings unto you.
Hello there, with these electricity costs spiking, we feel we are going to have to run the electricity cost numbers again. The cost of running AC per 1 hour is usually a constant hour run at 100% output. The SEER rating, for example, if you calculate the average output (you have weighted averages at 25%, 50%, 75%, 100% output) comes to an average output of 58%.
So, if you run an AC for 4 hours at an average 58% load, this is akin to running it for 2 hours and 19 minutes at 100% output. You can use that as the basis for AC running cost calculation. I know it sounds a bit complex, hope it helps.