Informational Guide

How Many BTU in a Ton?

Both tonnage and British thermal units are essential to show you which AC unit is adequate for your space.

by Josh M

Letting your air conditioner operate continuously can add a significant chunk to your monthly utility bill. So, it’s crucial to ascertain your air conditioner’s power capacity based on the room size.

Maintaining ideal cooling according to room size will help ensure low power consumption. This, in turn, will help you save money!

Make sure to check your AC unit’s BTU and tonnage ratings before purchasing one. But what exactly are BTUs and tonnage? Read on to know more about them:

The term AC tonnage is used for rating air conditioning systems. Tons (or tonnage) is the shorthand phrase, which denotes the air conditioner’s total cooling power in BTUs.

When an AC says it’s 3 tons, 4 tons, or 5 tons, it doesn’t refer to the unit’s weight. Instead, it refers to how much heat your AC unit can remove from the house in an hour.

On the other hand, BTU is an acronym for British Thermal Unit. It’s the unit to measure heat. It can be defined as:

“The amount of thermal energy needed to increase 1 pound of water temperature by one degree Fahrenheit.”

Almost all air conditioners mention their BTU rating at the back, which tells you how strong they are.

How Many BTU in a Ton?

One ton of AC unit can remove roughly 12,000 BTUs of indoor air per hour. This means there are 12,000 BTUs in a ton.

Believe it or not, the origin of this formula lies in the 19th-century ice-production and how much thermal energy one requires to melt 1-ton of ice in just 24 hours.

Modern science dictates that one ton translates to 12,000 BTUs.

Both tonnage and BTUs are essential to show you which AC unit is adequate for your space.

How to Convert BTU to Tons

In HVAC systems, the cooling and heating capacity is mentioned in either tons or BTUs. If you want to convert BTU to tons or tons to BTUs, you can use three different, straightforward methods.

Calculation Method

The first method is through an equation. Here’s a simple universal formula you can use to convert BTU to tonnage.

Tons = number of BTUs / 12000

For example, if you have an 18,000 BTU air conditioner and want to convert it to tons. Put the value into the tonnage equation:

Tons = 18000/12000 = 1.5 tons

However, to convert tons to BTUs, the following formula can be used:

Number of BTUs = tons x 12000

Here are some examples to give you a better understanding.

1 ton to BTU

Number of BTUs = 1 x 12000 = 12000 BTUs

1.5 tons to BTUs

Number of BTUs = 1.5 x 12000 = 18000 BTUs

5 tons to BTUs

Number of BTUs = 5  x 12000 = 60000 BTUs

Conversion Table

The second way to convert BTUs to tons and vice-versa is through a conversion table. It’s an easy way to refer to several converted values without going through tedious calculations.

Here’s a BTU to tons conversion table:

BTU Tonnage
12000 1 ton
18000 1.5 tons
24000 2 tons
30000 2.5 tons
36000 3 tons
48000 4 tons
60000 5 tons

The final way is through using a converter calculator. With the help of a calculator, you can effortlessly convert BTUs to tons on the move.

All you have to do is input BTUs to the calculator, and you’ll have the AC unit’s tonnage value.

How Much Air Conditioner Tonnage Do I Need?

When buying a new air conditioning system, make sure you get one with just enough tonnage to cool your room adequately.

To calculate your air conditioner tonnage requirements: multiply the area of your room by 25. It will show you how many BTUs you will require to cool the space.

Then, divide it by 12,000 to find the required tonnage for your new AC.

Apart from this, several other variables can impact your AC unit’s tonnage needs:

  1. .The existing insulation: Houses with good insulation keep cold air longer and more effectively. Plus, they need less tonnage capability to cool the space.
  2. .The existing landscape: Houses nestled under big trees will remain cooler than houses in open areas; they also require less tonnage.
  3. .The architecture: Normally, cooling the second or third story of your house is more complicated. Therefore, ranch-style homes are typically easier to cool. In short, fewer floors means less tonnage required.

People Also Ask (FAQ)

How Many Tons Is An Average Residential AC Unit?

Residential air conditioning systems typically range from one ton to five tons (or 12,000 BTU to 60,000 BTU). Anything above that falls into the category of light commercial air conditioning systems.

How Many Square Feet Does A Ton Of AC Cool?

Usually, a one-ton or 12,000-BTU air conditioning unit can cool down efficiently 400 square feet of space.

How Many Tons Of AC Do I Need For 1000/1600/2500 Square Feet House?

For a 1000 square feet house, a 1.5 tons AC unit is ideal. On the other hand, if you want to cool approximately 1600 and 2500 square feet of space, you’ll need 2.5 tons and 4 tons air conditioners, respectively.

Does Higher Tonnage Mean Higher Electricity Cost?

Yes, the more the tonnage of the AC, the higher the electricity bills.


Getting an AC unit with the correct tonnage and BTU ratings will help you get your preferred temperature, and you can also save money on energy bills.

You can achieve all this if you learn to translate tons and BTU ratings before purchasing a unit.

Josh M

My name is Josh and I am obsessed with the HVAC industry. I created this website to help HVAC techs of all levels get the best out of their heating & cooling systems. I have spent thousands of hours studying air conditioners, heaters and home air products so you can learn & buy with confidence. Learn more about the team here.