How Many Square Feet Does a Mini Split Cool? (BTU to Sq Ft)

Mini split coverage starts at about 300 square foot for a single zone system designed for a small room like a bedroom. Units in the 6,000 BTU to 8,000 BTU are ideal for use in a small room like a bedroom or office. The largest mini split heat pump systems are ideal for 2,500 to 3,000 square feet.

A Mini Split Sizing Calculator plus precise mini split sizing and coverage charts are included below.

Mini Split Size Calculator

Mini Split BTU to Square Foot Calculator

Example: What’s the 12,000 btu mini split room size?

It’s 600 square feet. Insert 12,000 btu into the calculator, and the answer is automatically calculated as 550 to 650 square feet.

How to Use This Calculator

In the Mini Split Cooling Capacity box, enter the heating and cooling capacity of the mini split system to get the results. Here’s another example:

What’s the 9,000 btu mini split room size?

It’s 450 sq ft. Simply type 9,000 into this calculator, and it will tell you that a unit this size has a cooling area of 400 to 500 square feet. This will work with any size mini split when you enter the BTU rating into the calculator. The calculation is instantaneous and accurate.

How many BTU is my AC?

Its capacity can usually be found right on the AC. Look for a metallic label or sticker on the side or back that contains the unit brand, model #, serial #, efficiency rating and capacity in BTUs.

Mini Split BTU to Room Size Chart

Mini Split Cooling CapacityRoom Size
7,000 BTU320 - 400 sq ft
9,000 BTU400 - 500 sq ft
12,000 BTU550 - 650 sq ft
15,000 BTU680 - 835 sq ft
18,000 BTU820 - 1,000 sq ft
24,000 BTU1,100 - 1,350 sq ft
30,000 BTU1,360 - 1,600 sq ft
36,000 BTU1,600 - 2,000 sq ft
42,000 BTU1,900 - 2,300 sq ft
48,000 BTU2,220 - 2,650 sq ft

* Based on average home in a moderate climate

How many square feet for an 18000 BTU mini split – meaning how big of a room or zone will it serve?

If you want to know what the 18000 btu mini split square footage is, for example, just find 18000 BTU in the left column of this BTU coverage chart and you will see that the answer is 820 to 1,000 sq ft. In the same manner, you can find that the coverage area of a 42,000 BTU system is 1,900 to 2,300 sq ft.

Also Read: Best Mini Splits For DIY

Mini Split Size Chart – Ton to Square Footage

1 – 5 Ton Mini Split Square Footage

Mini Split Cooling CapacitySquare Footage
1 Ton550 - 650 sq ft
1.5 Ton820 - 1,000 sq ft
2 Ton1,100 - 1,350 sq ft
2.5 Ton1,360 - 1,600 sq ft
3 Ton1,600 - 2,000 sq ft
3.5 Ton1,900 - 2,300 sq ft
4 Ton2,220 - 2,650 sq ft
5 Ton2,720 - 3,350 sq ft

* The chart is based on average home in a moderate climate

What’s the 1 ton mini split square footage?

1,100 to 1,350 square feet. Here’s how to use the chart to find out.

To determine the 1 ton mini split square footage that will be efficiently heated or cooled, simply locate 1 ton in the left column and find the answer to be 550-650 sq ft. Likewise, the 2 ton mini split square cover footage will be seen to be 1,100-1,350 sq ft.

Notice that with each of these charts, if you know the square footage of your room or rooms to be covered, you can find that number on the right side of the chart and find either the BTU or tonnage rating on the left side.

What Mini Split Sizing is and Why It’s Important

How efficiently your ductless mini split AC/Heating system will cool and heat your home will be largely determined by how well you sized it prior to purchase. Here is what you should know about mini split sizing before you make your selection.

If you were to measure the length and width of your foot before looking for a shoe to fit – that’s sizing. In the same way, by measuring the length and width of a room or other space in anticipation of purchasing a mini split – that’s sizing. You know what happens if you start wearing a shoe that’s too large or small, but what about installing the wrong size mini split?

Too small = Uncomfortable space and failed equipment. If the system is too small, you will not enjoy the level of comfort you want. Your unit may even run continuously, but will not be able to keep you comfortable when the outside temperature is very high or very low. The last thing you want is to have a mini split system installed that fails to be able to keep you cool or warm when you need it.

In addition, because the system will be operating at its maximum all the time, it will likely be prone to wear out more quickly if it is too small than a unit that was properly sized for the space it was intended for.

Bigger isn’t better! In fact, it could be worse. Installing a system that is too large may have even more drawbacks than if it were too small. First, a larger unit will almost always cost more, so you’ll spend more money than you really need to. Second, an oversized unit will probably “short-cycle”. This means that it will quickly heat or cool your space, but then shut off having satisfied the thermostat – only to start up again within a very short time. The third drawback – which is a result of short-cycling – is that the dehumidification process will also be cut short, and will not result in a comfortable environment.

How to Get the Best Mini Split Prices For Installation by Pros

  • Firstly, keep in mind that installation quality is always the most important thing for residential HVAC project. So never sacrifice contractor quality for a lower price.
  • Secondly, remember to look up the latest rebates as we talked above.
  • Thirdly, ask for at least 3 bids before you make the decision. You can click here to get 3 free estimates for your local contractor, and this estimate already takes rebates and tax credit into consideration and filter unqualified contractors automatically.

Lastly, once you chose the right contractor, remember to use the tactics from this guide: Homeowners Tactics When Negotiating with HVAC Dealer to get the final best price.


How many tons is a 12000 BTU Mini Split?

12,000 BTU is the same as 1 Ton. A mini split with this capacity will efficiently heat or cool a 550 to 650 square foot space.

What size mini split do I need for 400 square feet? 

9,000 to 12,000 BTU – that’s .75 to 1.0 tons aka tonnage.

Mini split for 1500 square feet?

36,000 to 45,000 BTU depending on where you live and home conditions. That’s roughly 3 to 4 ton mini splits.

How do you calculate mini split size?

The exclusive Pick HVAC Mini Split BTU Calculator is the way to do it. The Mini Split Size Calculator answers the question: What Size Ductless AC/Heat Pump Do I Need? Check it out.

How many watts is a 12 000 BTU Mini Split?

1 BTU is equal to 0.293 watts, so 12,000 BTU is the equivalent of 3,516 watts. To calculate any BTU to watts, simply multiply the BTU by .293.

When calculating the size, is it ok to slightly oversize mini split?

As a rule of thumb, it’s best to select a mini split that is rated for the particular area you want covered. However, if you’re going to be using the unit in an area that is not well insulated – like a garage, for example – it’s ok to go one size higher.

Similarly, if you have a basement that is very cool and damp, you might choose a unit that is slightly higher than that recommended in the charts. In both situations, the key word is “slightly”, remembering that a unit that is too large can have several negative results.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.
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