Watts vs. BTUs: What Are They?

September 27, 2021

When working in information technology (IT), a thorough understanding of units of energy and the correct usage of terminology is crucial to ensuring accuracy in your position. Two commonly used and often misunderstood terms in IT are watts and BTUs (British Thermal Units).

The more accurate your understanding of these terms, the better you’ll perform in the tech industry.

BTUs vs. Watts

Watts and BTUs are both essential factors in determining your data center cooling needs.

Understanding the relationship between BTUs and watts is a fundamental skill for IT professionals. These units are used in basic formulas to calculate the total tons of cooling needed to maintain the optimal temperature for a data center system.


One British thermal unit is the amount of energy it takes to increase a pound of water by 1 degree Fahrenheit. This unit is a standalone factor and is not associated with a relative time.


The term “watts” denotes a unit of measurement of power. When used in IT-related formulas, one watt is approximately the equivalent of 1 volt-ampere (VA). For this reason, the terms watts and VA are often used interchangeably in an IT context.

Multiply the voltage of something by its amps to find the total number of watts. This number refers to the rate at which energy is transferred, typically in joules per second. A wattage measurement is always associated with a time factor.

How Are They Different?

Although watts and BTUs are both units of energy, they measure two different aspects of how energy is transferred.

The key difference between watts and BTUs is that the latter is a measurement of energy, a standalone factor in physics. In contrast, wattage denotes the rate of energy transfer, which is always relative to a time factor.

You can convert watts into BTUs using a standard formula, and doing so is common practice to calculate data center cooling requirements.

How Do Watts and BTUs Relate to Data Center Cooling?

You need both BTUs and watts to determine the cooling requirements for your data system. Using standard formulas, you can convert watts into BTUs and find the tons of cooling necessary to keep your data center at the ideal temperature.

Follow the steps below to calculate the tons of cooling you need:

  1. Voltage x amps = watts
  2. Watts x 3.41 = BTUs per hour
  3. BTUs per hour / 12,000 = tons of cooling

The tons of cooling number tells you what is required to cool your data center system and prevent overheating.

Contact DataSpan for Effective Cooling Solutions

Calculating your data center cooling needs is crucial to maintaining properly functioning equipment. DataSpan has 50 years of experience in the IT industry. We are equipped to calculate your cooling needs and design, install and maintain proper cooling systems that meet your specific requirements.

You can contact us for immediate answers to your questions or fill out a form to find your rep today and get the service you need.