Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture Money Videos
British thermal unit
Table of Contents
Introduction References & Edit History Quick Facts & Related Topics
Quizzes
Electric power lines against sunset (grid, power, wires, electrical, electricity)
Energy & Fossil Fuels
Related Questions
Read Next
Highway Night Traffic Portland, drive, driving, car, automobile.
What's the Difference Between Speed and Velocity?
Blackboard inscribed with scientific formulas and calculations in physics and mathematics
The World Science Festival’s Pioneers in Science
Laboratory glassware (beakers)
5 Quizzes That Will Tell You Whether You Should Have Been a Scientist
Abstract vector hi speed internet technology background
History of Technology Timeline
Muscle injury. Man with sprain thigh muscles. Athlete in sports shorts clutching his thigh muscles after pulling or straining them while jogging on the beach.
Why Does Heat Relax Your Muscles?
Discover
New York NY/ USA- November 23, 2018 Hordes of shoppers throng the Macy's Herald Square flagship store in New York looking for bargains on the day after Thanksgiving, Black Friday.
Why Is It Called Black Friday?
The Colosseum, Rome, Italy. Giant amphitheatre built in Rome under the Flavian emperors. (ancient architecture; architectural ruins)
New Seven Wonders of the World
David Cameron. President Barack Obama and Prime Minister David Cameron of the United Kingdom talk during the G8 Summit at the Lough Erne Resort in Enniskillen, Northern Ireland, June 17, 2013
What’s the Difference Between a President and a Prime Minister?
Leonardo da Vinci (1452-1519), Italian Renaissance painter from Florence. Engraving by Cosomo Colombini (d. 1812) after a Leonardo self portrait. Ca. 1500.
10 Famous Artworks by Leonardo da Vinci
United States elections portal page linking to each election interactive
A History of U.S. Presidential Elections in Maps
An ancient egyptian hieroglyphic painted carving showing the falcon headed god Horus seated on a throne and holding a golden fly whisk. Before him are the Pharoah Seti and the goddess Isis. Interior wall of the temple to Osiris at Abydos, Egypt.
11 Egyptian Gods and Goddesses
Washington DC.,USA, April 26, 1989. Supporters for and against legal abortion face off during a protest outside the United States Supreme Court Building during Webster V Health Services
Pro and Con: Abortion

British thermal unit

unit of measurement
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
Print
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Share
Share to social media
URL
https://www.britannica.com/science/British-thermal-unit
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
Also known as: BTU
Written and fact-checked by
The Editors of Encyclopaedia Britannica
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. They write new content and verify and edit content received from contributors.
The Editors of Encyclopaedia Britannica
Article History
Related Topics:
heat
unit
See all related content

British thermal unit (BTU), a measure of the quantity of heat, defined since 1956 as approximately equal to 1,055 joules, or 252 gram calories. It was defined formerly as the amount of heat required to raise the temperature of one pound of water 1° F. The definition was changed because it was dependent on the initial temperature of the water. Gas utilities frequently use a larger unit, the therm, defined as 100,000 BTU, as a measure of gas consumption.