*What size air conditioner do I need? *

There are several metrics you should consider before buying an air conditioner. You have different EER and SEER ratings, power, amperage, voltage, and so on.

The **most important** metric is the cooling capacity (measured in BTU/hr). It denotes the **size of your air conditioner**.

BTU meaning: British Thermal Unit or BTU/h is a unit that determines the cooling/heating power of an HVAC device (air conditioner, furnace, etc.).

What is BTU is an AC unit? Simply put, it’s the capacity or power of the AC.

*The bigger the BTU, the more cooling effect an AC unit can provide.*

Here is an example of how you can calculate how many BTUs you need to cool down a 500 sq. ft. area with 8 feet ceilings, average sun exposure, average climate, and not including kitchen *(you can find this BTU calculator below and use it for your situation; with 4,000-24,000 BTU room size table)*:

In short, you would need a **10,000 BTU air conditioner**.

*How many BTUs do you need to cool down certain square footage of space properly? *

There are only 2 rules:

**Not too big.**Obviously, you don’t want a 14,000 BTU window air conditioner for a small 12×12 room because it unnecessarily boosts your energy bill.**Not too small.**You don’t want to get hot in the summer because you bought a 6,000 BTU portable air conditioner for a 1,000 sq ft apartment.

The BTU needed to cool down a room of known footage that can be calculated. According to The U.S. Department Of Energy recommendation for the size of room air conditioners:

“…an air conditioner generally needs

of living space.”20 BTUfor eachsquare foot

Based on room size, ceiling height, and other conditions, you can calculate how many BTU air conditioner you need:

## Air Conditioner BTU Calculator

As you can see, the sq ft to BTU converter neatly gives you an idea of what size of air conditioners you should be looking at in an ‘sq ft to BTU’ kind of way.

If you want to properly cool down a 300 square foot area (or room), you need a 6,000 BTU air conditioner. Obviously, the problem arises when you have a tiny**12×12 room**, for example. According to the US Department of Energy directive, an air conditioner’s most appropriate size would be 2,880 BTU unit. The best you can do here is to buy a small 5,000 BTU window or a small 8,000 BTU portable AC unit (more about the smallest AC units here).

The trendy portable air conditioners, for example, have a cooling capacity of 6,000 BTU to 14,000 BTU. According to Go Downsize, the average size of studio apartments in the US is about 500 sq ft. That means that for a small apartment, you don’t need expensive central air conditioning. You can install an average-sized 10,000 BTU portable air conditioner, which will save you tons of money.

*Pro tip:* Always buy a ** little bigger AC unit** than this recommendation. Example: When you use the BTU calculator below and get, let’s say, 10,000 BTU for a 500 sq ft area, start looking for a 12,000 BTU air conditioner. Your electricity bill will be a little higher, but you won’t need to sweat if you bought an AC unit that’s too small.

To better illustrate what size of an air conditioner you need, let’s have a look at a BTU chart:

### Air Conditioner BTU Chart; With 12,000 BTU (1 Ton) Room Size Example

*Question:* What is the **12,000 BTU air conditioner room size**? 12,000 BTU is equal to 1 ton; we’re talking about 1 ton AC room size.

*Answer:* Using the EPA’s 20 BTU per sq ft rule of thumb, the room size of 12,000 BTU air conditioners is 600 sq ft. Equally, 1 ton AC room size is about 600 sq ft.

Here is a table with rough room size estimates for air conditioners with different cooling capacities to help you out:

Cooling Capacity (BTU): | Room/Area Size: | Examples: |
---|---|---|

4,000 BTU air conditioner room size: | 100-200 sq ft | 10x10 room, 12x12 room, 14x14 room |

6,000 BTU air conditioner room size: | 200-300 sq ft | 16x16 room, tiny apartment |

8,000 BTU air conditioner room size: | 300-400 sq ft | 18x18 room, 20x20 room |

10,000 BTU air conditioner room size: | 400-500 sq ft | 22x22 room, small studio apartment |

12,000 BTU air conditioner room size: | 500-600 sq ft | 24x24 room, average studio apartment |

14,000 BTU air conditioner room size: | 600-700 sq ft | 2 rooms, small apartment |

16,000 BTU air conditioner room size: | 700-800 sq ft | 2 rooms, average apartment |

18,000 BTU air conditioner room size: | 800-900 sq ft | 3 rooms, above average apartment |

20,000 BTU air conditioner room size: | 900-1,000 sq ft | 3 rooms, larger apartment |

24,000 BTU air conditioner room size: | 1,000-1,200 sq ft | 4 rooms, large apartment |

*Example:* How many BTU do you need for a 20×20 room? For a 20×20 room, you need about 10,000 BTU of cooling output.

Again, when narrowing down your choice of an air conditioner, knowing how big an area you need to cool is your best friend. Based on that, you can calculate sq ft to BTU and immediately know what range of BTU values your perfect AC unit should be.

If, for example, you buy a 14,000 BTU portable air conditioner to cool down a 12×12 room, you will have a chill cold room and more than $100/year unnecessary cost on your electricity bill.

### Perfect BTU Air Conditioner For Room Sizes

As recommended by The U.S. Department of Energy, the ballpark figure is **20 BTU per sq ft**. That is a very good estimate already.

The simplest BTU calculation formula for an air conditioner looks like this:

**BTU = Square Footage× 20**

However, to get a perfectly-sized air conditioner with just right enough cooling power and no energy overspending, you should consider some additional factors. These are:

**Room height.****Local climate.****Sun exposure.****The number and size of the windows.**

The BTU calculator and chart work best for standard room height. Obviously, if you have a tall ceiling (older buildings have +10 ft ceilings), you have to add a bit of cooling power in BTU.

There is also a difference if you live in Texas or New York. The local climate in Texas is, on average, hotter, and therefore you should need an air conditioner with a few 1,000 BTU more.

The same goes for sun exposure. If the room or area you’re looking to cool down is generally facing the sun, you will need a bigger air conditioner.

Additionally, the walls do block the sun very effectively. Windows don’t. If you have big windows and many of them, the sun will heat your house more.

In summary, when do you need an air conditioner with higher BTU than standardly recommended:

- If you have
**high walls**. - If you live in a
**hot climate**. Examples: California, Texas, Florida, New Mexico, and so on. - If the particular room you want to cool down is
**facing the sun**more often than not. - If you have an
**above-average size and number of windows**.

*Example:* If you have a 500 sq ft sun cabin near Texas with many glass windows, you should be looking at 10,000 BTU air conditioners (as recommended). It would be best if you were looking at 14,000 BTU portable air conditioners, for example.

### What Does BTU Mean In Air Conditioners (Summary)

BTU in air conditioners is simple a metric of how much cooling effect that particular AC unit can produce.

We want an air conditioner that has just the right amount of cooling effect. That’s why by knowing the square footage of the area we want to cool down, we can calculate how many BTUs should our air conditioner have.

The equation for ‘sq ft to BTU‘ is quite simple – multiply the sq ft with 20. That means that a 500 sq ft room needs a 10,000 BTU air conditioner. Of course, do make sure to buy an AC unit that is a bit stronger if you have high ceilings, live in a hot climate, and have an above-average sun in those rooms.

For smaller spaces (example: camping air conditioners for tents), you can use portable battery-powered AC units.

You should use the BTU calculator when choosing different types of air conditioners, including:

- Mini-split AC units. Example: Mr Cool mini-split units have the highest SEER rating of above 20 EER.
- Portable air conditioners. Here you can check the biggest (up to 15,000 BTU), quietest (below 50 dB), and portable AC with heater units. These are the best portable AC units for apartments, for example.
- Window AC units. Here you can check the biggest (24,000+ BTU), quietest (below 42 dB), and window AC units with heaters. Special kinds of window AC units include casement window AC units, through-the-wall AC units, saddle window AC units, and low-profile window units.

*Note:* Evaporative coolers and mini personal air coolers do not produce a cooling effect that can be expressed in BTU. They use water evaporation instead of the refrigerant-based system to provide a cooling effect.

You can also check a similar BTU calculator for heating here.

We hope this helps. If you have any questions about your particular room or area you’re buying an air conditioner for (and don’t know how many BTU ones you should take), you can ask in the comments, and we’ll try to give you an answer as soon as possible.

## FAQs

### How big of an AC do I need calculator? ›

To calculate the size of the air conditioner you need for a room, first, **multiply the length of the room with its width**. Then multiply it with 25 BTU to get the ample cooling for the room under different weather conditions. For example, if the room is 15 feet long and 12 feet wide, it comes to 180 square feet.

### What size room will a 12000 BTU air conditioner cool? ›

12,000 BTUs will cover **400 sq.** **ft.** (3,200 cubic feet) 13,000 BTUs will cover 450 sq.

### How many square feet will a 25000 BTU air conditioner cool? ›

The Frigidaire 25,000 Window-Mounted Room Air Conditioner is designed to cool up to **1,600 sq.** **ft**. and keep large rooms comfortable.

### How do I calculate air conditioner for a room? ›

First, **find out your the area of you room.** **Then divide it by 600 to get the basic capacity**. So, if you room is 100 sq. feet, the basic AC capacity required will be 0.167 tons (100 / 600).

### How do I calculate air conditioner size for a room? ›

To calculate the size, simply **multiply the length times the width of the room or area to be cooled.** **Then, as a practical number, multiply that total times 25 BTU**. This allows ample cooling, whether it is a rainy, moist day or a hot, sunny, humid day.

### What size AC do I need for 1500 square feet? ›

Rule of thumb: You'll need approximately 20 BTU of cooling per square foot of space. For example, a 1,500-square-foot home will require roughly **30,000 BTU**.

### How big of an AC do I need for 1200 sq ft? ›

ZONE 1 | ZONE 2 | |
---|---|---|

1.5 Tons | 600 - 900 sf | 600 - 950 sf |

2 Tons | 901 - 1200 sf | 951 - 1250 sf |

2.5 Tons | 1201 - 1500 sf | 1251 - 1550 sf |

3 Tons | 1501 - 1800 sf | 1501 - 1850 sf |

### What size AC do I need for 2500 square feet? ›

Home Sq Footage | Air Conditioner Size (tons) |
---|---|

1,000 – 1,500 square feet | 2 tons |

1,500 – 2,000 square feet | 3 tons |

2,000 – 2,500 square feet | 4 tons |

2,500 – 3,300 square feet | 5 tons |

### What size room will a 10000 BTU air conditioner cool? ›

How many square feet will a 10000 BTU AC cool? Using the AC Cooling Capacity Calculator or the AC Size to Room Size Table, you can see that a 10000 AC will cool up to 500 square feet.

### What size room will a 8000 BTU air conditioner cool? ›

8,000 BTU air conditioners are considered one of the smallest AC units. The 8,000 BTU (British Thermal Units) capacity might be enough for a good-sized room or even a small apartment. How big of a room will 8000 BTU cool? 8,000 BTU air conditioners can cool down rooms from 250 sq ft (about 16×16) to 400 sq ft (20×20).

### What size room will a 6000 BTU air conditioner cool? ›

In general, a 5,000 to 6,000 BTU air conditioner can cool **between 100 and 300 square feet**. Seven thousand to 8,200 BTU units are adequate for cooling 250 to 550 square feet, while 9,800 to 12,500 BTU models cool up to 950 square feet.

### How big of a room can a 24000 BTU AC cool? ›

### How many square feet will a 24000 BTU air conditioner cool? ›

Key Specs. Get relief from hot, muggy days with a KingHome Energy Star window-mounted air conditioner. KingHome's 24,000 BTU window AC is a great choice to cool and dehumidify a room up to **1,500 square feet**. Use it to cool any room of your home - bedroom, living room, family room, dining room, or home office.

### What size room will a 24000 BTU air conditioner cool? ›

### How many BTU do I need for a 20x20 room? ›

As a general rule, a 20×20 feet or 400 square feet room should use a **12,000 BTU** or 1 Ton air conditioner. If your room is heavily shaded, you can save cost by using a 9,000 BTU or 0.75 Ton air conditioner.

### Which AC is better for 12x12 room? ›

According to Energy Star, a 12×12′ or 144 sqft room requires **5,000 BTU of cooling capacity when occupied by two persons**. If the room is heavily shaded, it only requires 4,500 BTU. If the room is very sunny, it requires 5,500 BTU. For each additional person, you need to add 600 BTU.

### How many BTU do I need for a 12x12 room? ›

Usually, a 12 x 12 room needs **5,000 BTU of cooling capacity when used by two people**. If the space is not getting direct sunlight, you only need 4,500 BTU. However, depending on how many people use the room, it can take upwards of 6,000 BTU to cool a 12 x 12 space.

### How many square feet will a 1.5 ton AC unit cool? ›

A 1.5-ton AC unit covers **900 square feet** of living space.

### What is the room size for 1.5 ton AC? ›

Room size and power consumption

Here tonnage plays an important role. For instance, a 1-ton window AC or a 1.5 ton split AC is an ideal choice for rooms measuring up to **150-160 sq ft**.

### How many HP is 24000 BTU? ›

To convert BTU to HP, divide BTU by 9000.

Similarly, a 24000 BTU air conditioner is equivalent to a **2.5 HP** air conditioner.

### How many BTUs do I need to cool 1500 square feet? ›

The next step is to determine how many BTUs are needed to cool that space. While there is no specific formula for this, the general rule of thumb is 20 BTUs per square foot you are cooling. So, if your home is 1,500 square feet, you'll need an air conditioner with **30,000 BTUs**.

### What size AC do I need for 2000 square feet? ›

If your home is 2000 square feet, you can calculate your HVAC needs the same as you would for a 1600 square foot home. Assuming one ton of cooling capacity can cool 400 square feet of your home, you'll need about **5.0 tons** of air conditioning capacity. Multiply this by 12,000 BTUs, and you'll get 60,000 BTUs.

### How many square feet does a 3.5 ton AC cool? ›

A 3.5-ton AC unit cools **2,000 to 2,200 sq.** **ft**., depending on the insulation and climate.

### How much is a new AC unit for a 1500 sq ft house? ›

Home Size | Average Costs (Installed) |
---|---|

1,000 sq.ft. | $2,500 - $6,000 |

1,500 sq.ft. | $3,750 - $9,000 |

2,000 sq.ft. | $5,000 - $12,000 |

2,500 sq.ft. | $6,250 - $15,000 |

### Is 16 SEER worth the extra money? ›

A 16 SEER unit is about 13% more efficient than a 14 SEER. **For every $100 you spend to cool your home with a 14 SEER, you could save $13 on your monthly bill by upgrading to the 16 SEER unit**. But just like gas mileage, your ability to meet this maximum efficiency and savings depends on a lot of other factors.

### Is 1.5 ton AC enough for 300 square feet? ›

**If a Room sq ft is above 201-300 sq ft, then go for 1.25 or 1.5 Ton AC**. 4. If a Room is big say above 301-500 sq ft, then better go for 1.5 Ton AC.

### How many BTU do I need per square foot? ›

As a general rule, an air conditioner needs **20 Btu** for each square foot of living space. But other considerations, such as the ceiling height and the size of your windows and doorways, might call for more cooling power. To measure your room, multiply the length by the width.

### What size AC unit do I need for a 1400 sq ft house? ›

Air Conditioning Sizing Chart: | |
---|---|

550 to 700 sq ft | 14,000 BTUs |

700 to 1,000 sq ft | 18,000 BTUs |

1,000 to 1,200 sq ft | 21,000 BTUs |

1,200 to 1,400 sq ft | 23,000 BTUs |

### What size AC unit do I need for a 1800 sq ft house? ›

Here's some math: You need around 20 BTUs per square foot, which is equivalent to 0.0016 tons. For example, a 600-square-foot space requires a 12,000 BTU or 1-ton unit. By those calculations, an average 1,800-square-foot house would need a **3-ton** central air conditioning unit.

### What size room will a 9000 BTU air conditioner cool? ›

**350 – 400 sq.** **feet**: 9,000 BTUs.

### How many square feet will a 14000 BTU cool? ›

In our experience, a 12,000 BTU portable can work well in a bedroom up to about 200 square feet, and a 14,000 BTU unit will make some difference up to 400 square feet if you can tolerate the noise.

### Is 12000 Btu too much? ›

As a guide, consider 5,000-BTU models for rooms 150 square feet or smaller, 8,000 BTUs for medium-size rooms (340 square feet), and 12,000 to 14,000-BTU models for rooms with square footage from 550 to 800. Having the correct power is imperative.

### Is 9000 BTU enough for a bedroom? ›

The larger the size of the room, the higher the BTU of the air-conditioner should be. Small rooms (150 square feet or below) will require a unit with around 6,000 BTUs. This is generally appropriate for a single bedroom. **For larger rooms (up to 350 square feet), you will need a unit with around 9,000 BTUs**.

### Does higher BTU use more electricity? ›

**The more BTU your unit produces, the more energy it consumes**. So, if you are worried about high energy costs, you should get a unit that is appropriate for your space.

### What will 12000 Btu cool? ›

The most common window air conditioning units come in cooling capacities ranging from 5,000 to 12,000 Btu. A 12,000 Btu air conditioner can cool between 450 and 550 square feet of floor space. A 12,000 Btu unit could cool a room 25 feet long by 20 feet wide that has 500 square feet of floor area.

### Is 7000 BTU enough for a bedroom? ›

**As a general rule we advise you to buy an Air Conditioner with a minimum 7000BTUs** as this is the minimum required to call a small room (18sq/m) on a hot day. Medium rooms (24sq/m) need around 10,000BTUs and larger rooms and office spaces (36sq/m) require around 15000BTUs.

### How do you calculate BTU cooling requirements? ›

**Step 1: Measure The Square Footage (Length, Width, Height Exact To 0.25 Ft)**

- Square Footage = Measured Length x Measured Width.
- Square Footage = 16 3/4 ft (Length) x 14 1/2 ft (Width) = 243 sq ft.
- BTU Requirement = 500 sq ft x 20 BTU per sq ft = 10,000 BTU.
- Accurate BTU Calculation = 20,000 BTU * 1.1 + 600 BTU = 22,600 BTU.

### What will a 5000 BTU air conditioner cool? ›

“5000 BTU air conditioner can cool a **100 to 150 sq ft room**.” Energy Star guidelines for 5000 BTU AC room sizing also recommends that you: Increase capacity for a room with high sun exposure; +10% cooling output. That would reduce the 5000 BTU AC room size to 90-135 sq ft.

### How many BTUs do I need to cool 1000 square feet? ›

You'll see that 1000 square feet of space needs about **20,000 BTU** for cooling. Some window air conditioners deliver 20,000 BTU. For mini split or central air, you'll have to decide on whether to go a little small at 1.5 tons or 18,000 but or go up to a 2-ton, 24,000 BTU system.

### What is the difference between a 3 ton and 3.5 ton AC unit? ›

The bigger the size of the air conditioner is the more heat it removes. Generally, a 1-ton air conditioner unit can remove 12,000 BTUs of air per hour. **A 3-ton AC unit can remove, (3×12,000)=36,000 BTUs of air per hour.** **Similarly, 3.5-ton AC removes, (3.5×12,000)=42,000 BTUs of air per hour**.

### Is a 2 ton AC big enough? ›

For those of you that don't understand the way AC systems work, **a 2-ton unit typically provides cooling for about 900-1,400 square feet of space** – give or take.

### What size air conditioner do I need for a 2400 square foot home? ›

The answer to the question, “what size AC unit for 2400 square feet?”, would be, is 60,000 BTUs or 5 Tons.

### How many BTU do I need for a 20x20 room? ›

As a general rule, a 20×20 feet or 400 square feet room should use a **12,000 BTU** or 1 Ton air conditioner. If your room is heavily shaded, you can save cost by using a 9,000 BTU or 0.75 Ton air conditioner.

### How many BTU do I need for a 12x12 room? ›

Usually, a 12 x 12 room needs **5,000 BTU of cooling capacity when used by two people**. If the space is not getting direct sunlight, you only need 4,500 BTU. However, depending on how many people use the room, it can take upwards of 6,000 BTU to cool a 12 x 12 space.

### What size room will a 8000 BTU air conditioner cool? ›

8,000 BTU air conditioners are considered one of the smallest AC units. The 8,000 BTU (British Thermal Units) capacity might be enough for a good-sized room or even a small apartment. How big of a room will 8000 BTU cool? 8,000 BTU air conditioners can cool down rooms from 250 sq ft (about 16×16) to 400 sq ft (20×20).

### What size room will 15000 BTU cool? ›

Air conditioners rated at 15,000 Btu should be enough to cool most rooms **up to about 875 sq.** **ft**.

### How many BTU do I need for a 12x24 room? ›

Room Type | Room Size | Recommended BTU |
---|---|---|

12 x 12 room | 144 sq ft | 5,000 BTU |

12 x 24 room | 576 sq ft | 12,000 BTU |

13 x 13 room | 169 sq ft | 6,000 BTU |

14 x 16 room | 224 sq ft | 6,000 BTU |

### What size room will a 10000 BTU AC cool? ›

How many square feet will a 10000 BTU AC cool? Using the AC Cooling Capacity Calculator or the AC Size to Room Size Table, you can see that a 10000 AC will cool up to 500 square feet.

### What size AC do I need for 1500 square feet? ›

Rule of thumb: You'll need approximately 20 BTU of cooling per square foot of space. For example, a 1,500-square-foot home will require roughly **30,000 BTU**.

### Is 8000 BTU enough for a bedroom? ›

Is An 8,000 BTU Unit Appropriate For Your Needs? An 8,000 BTU window AC or portable air conditioner is **capable of cooling most standard bedrooms and offices**. If you want to cool a larger space or multiple rooms, an 8,000 BTU air conditioner does not have enough power.

### Is 7000 BTU enough for a bedroom? ›

**As a general rule we advise you to buy an Air Conditioner with a minimum 7000BTUs** as this is the minimum required to call a small room (18sq/m) on a hot day. Medium rooms (24sq/m) need around 10,000BTUs and larger rooms and office spaces (36sq/m) require around 15000BTUs.

### What size room will a 6000 BTU air conditioner cool? ›

In general, a 5,000 to 6,000 BTU air conditioner can cool **between 100 and 300 square feet**. Seven thousand to 8,200 BTU units are adequate for cooling 250 to 550 square feet, while 9,800 to 12,500 BTU models cool up to 950 square feet.

### What size room will a 7000 BTU air conditioner cool? ›

**250 – 300 sq.** **feet**: 7,000 BTUs.

### Is 8000 BTU too much for a small room? ›

As a guide, consider 5,000-BTU models for rooms 150 square feet or smaller, **8,000 BTUs for medium-size rooms (340 square feet)**, and 12,000 to 14,000-BTU models for rooms with square footage from 550 to 800. Having the correct power is imperative.

### Is 9000 BTU enough for a bedroom? ›

The larger the size of the room, the higher the BTU of the air-conditioner should be. Small rooms (150 square feet or below) will require a unit with around 6,000 BTUs. This is generally appropriate for a single bedroom. **For larger rooms (up to 350 square feet), you will need a unit with around 9,000 BTUs**.

### What happens if BTU is too high? ›

If your air conditioner has a bigger BTU rating than the room size needs, **it will cycle off too quickly, waste energy, and will not adequately dehumidify the space**. So a higher BTU than needed is definitely not recommended.

### Is it better to oversize or undersize AC? ›

Not surprisingly, **an undersized air conditioner will struggle to cool your home**. It'll run longer cycles than it should since the square footage it's trying to cool is simply too large for its output capacity. On the other hand, an oversized unit will short cycle, meaning it'll turn on and off in short bursts.

### How many square feet will a 14000 BTU cool? ›

In our experience, a 12,000 BTU portable can work well in a bedroom up to about 200 square feet, and a 14,000 BTU unit will make some difference up to 400 square feet if you can tolerate the noise.