Skip to main content
We are Hiring! See Open Positions & Apply Now.
York Air Conditioning Products

Call Now! We'll be Right Over.

(941) 474-3691

Proudly Serving
Sarasota and Charlotte County

Home » Cool Tips » BTU and Tonnage Calculator

BTU and Tonnage Calculator

Calculate What AC Size Your Home Needs

The size (cooling capacity) of your air conditioner is measured in BTU (British thermal unit) and tons (12,000 BTU = 1 ton). How much cooling capacity should your air conditioner have to keep your home comfortable? Use our free BTU and tonnage calculator to find out!

How to Use the BTU and Tonnage Calculator

Although, at Kobie Complete, we factor in many details to determine the exact BTU your new air conditioner should have, our free online BTU and Tonnage Calculator will give you a rough estimate. Just fill in your home’s square footage, the number of occupants, and the number of windows in the form below.

You may also be interested in our SEER Energy Savings Calculator. See instantly how much money you can save by upgrading to a more efficient air conditioner!

BTU and Tonnage Calculator

Typical Tonnage by SQFT

750 to 1,0002
1,050 to 1,4002.5
1,450 to 1,7003
1,750 to 1,9003.5
1,950 to 2,2004

Our BTU and Tonnage Calculator is Based on the Following:

  • 23 BTU per square foot
  • 200 BTU per window
  • 200 BTU per occupant

These factors are meant to give you a general idea of how much air conditioning your home requires. A more detailed load calculation will include other factors, such as the size and location of the windows, the direction your house faces, air leakage, the state of your home’s ductwork, and more.

Normally, a Manual J load calculation is performed in new construction. When replacing an AC in an existing home, unless there were considerable renovations or other changes to the structure that would affect the cooling load, an HVAC contractor may not consider a detailed load calculation necessary.

Contact Kobie Complete (or your local HVAC dealer if you live outside Sarasota and Charlotte County, Florida) for more information on how to get a precise load calculation for your home.

Why is AC Sizing Important?

Air conditioners are not “one size fits all”. Each home has a different cooling load and thus requires a different size air conditioner. An air conditioner that is too large or too small for your home will negatively affect its ability to cool and dehumidify. Also, it will impact your electric bill.

An oversized air conditioner:

  • Cycles on an off frequently (a.k.a. short cycling)
  • Causes electric bills to rise
  • Creates additional wear and tear on AC components and ductwork
  • Shortens the AC unit’s lifespan
  • Doesn’t remove enough humidity, facilitating mold and mildew growth

An undersized air conditioner:

  • Runs constantly
  • Doesn’t provide enough cooling
  • Causes electric bills to rise

Are you experiencing any of these problems with your current air conditioner? Ask Kobie Complete (or your local HVAC dealer) whether your unit may be under- or oversized.

Learn more about AC Sizing

How to Find Your Current Air Conditioner’s Tonnage or BTU Rating

First, locate your air conditioner’s model number. The model number is generally written on the side of your air handler or condensing unit. Otherwise, you should be able to find it in the manual.

An air conditioner’s model number is a string of numbers and letters. Within the string, you should see an even, two-digit number. Add three zeroes to the number and you have the BTU rating. Divide the two-digit number by 12, and you have the tonnage.

Here are some examples:

  • 12 = 12,000 BTU or 1 ton
  • 18 = 18,000 BTU or 1.5 tons
  • 24 = 24,000 BTU or 2 tons
  • 30 = 30,000 BTU or 2.5 tons
  • And so on…

Some HVAC dealers also list the unit’s tonnage or BTU on their sales estimates or invoices.

Fill Out the Form Below for a Free AC Replacement Quote from Kobie Complete

Need a new air conditioner in Sarasota or Charlotte County? Call us today at (941) 474-3691 or fill out this form to get a free, no-obligation quote:

    This form collects your personal information so that we can process and reply to your request for an estimate on a new air conditioner. Check out our Privacy Policy for more details.

    Disclaimer: The BTU and Tonnage calculator is designed to give you a rough estimate on what size air conditioner you need. You should not base your AC purchasing decision on this calculator. A detailed load calculation is required to determine your home’s precise cooling load. Please contact your HVAC dealer to help you determine what size is right for your home.

    For emergency service, please call:
    (941) 474-3691

      This form collects your personal information so that we can process and reply to your request. Check out our Privacy Policy for more details.