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BTU Calculator Truly Honest. Truly Local.

BTU Calculator


Here at Thomas Service Company, we want to ensure that people are able to identify the right HVAC system for their homes.

Many people don't realize that you can have an undersized HVAC unit as well as an oversized one. Either way is bad for efficiency as well as for the unit itself.

We genuinely appreciate your business and want to ensure that we help you in any way possible, which is why we've added the FREE BTU calculator.

You can use this BTU calculator to better decide on the HVAC system for your home based on the most important contributing factors, such as size, insulation, type, climate, and more.

square feet

What are BTUs & What Rule Do They Play in HVAC

British Thermal Units, or BTUs, are a measure of energy. In the context of heating, ventilation, and air conditioning (HVAC), BTUs are used to describe the capacity of a system to heat or cool a space. For example, a small room might require 10,000 BTUs of cooling capacity, while a larger room might need 20,000 BTUs.

  • A BTU is an approximate energy that is needed to heat one pound of water by 1 degree Fahrenheit.
  • 1 BTU = 1,055 joules, 252 calories, 0.293 watt-hours, or the energy released by burning one match.
  • 1 watt is approximately 3.412 BTU per hour.

Why Sizing Matters for Your HVAC System

When shopping for an HVAC system, it's important to choose one that has the appropriate BTU rating for the space it will be used in. Otherwise, the system will either be overworked (and possibly break down) or it won't be able to effectively cool the space. With a little bit of research, you can easily find an HVAC system with the right BTU rating for your needs.

Which is why we have provided our BTU calculator here on this page for anyone to use for free! When it comes to finding the BTU rating for your needs, there are a few factors to take into consideration. These include The square footage, type of room, type of insulation, how much sun exposure there is, and the climate.

The Thomas Promise

Unparalleled Expertise and a Passion for Service
  • We Are Founded on Honesty & Integrity

    We genuinely appreciate your business and we strive to do things the right way.

  • We Arrive at Your Home On Time

    HVAC and plumbing needs can't always wait. Call our experts for immediate help.

  • We Will Not Leave a Mess in Your Home

    We genuinely appreciate your business, and we strive to do things the right way

  • We Do What it Takes to Make You Comfortable

    We're so confident you'll be happy with our home comfort services, we guarantee it.

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