Science, Tech, Math › Science How to Convert Feet to Inches Feet to Inches Conversion Formula and How to Use It Share Flipboard Email Print Jack Hollingsworth / Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated August 30, 2018 Feet (ft) and inches (in) are two units of length, most commonly used in the United States. The units are used in schools, daily life, art, and some areas of science and engineering. The feet to inches conversion is useful and important, so here's the formula and examples that show how to convert feet to inches and inches to feet. Feet to Inches Formula This conversion isn't quite as easy as converting between metric units, which are simply factors of 10, but it's not difficult. The conversion factor is: 1 foot = 12 inches distance in inches = (distance in feet) x (12 inches/foot) So, to convert a measurement in feet to inches, all you need to do is multiply the number by 12. This is an exact number, so if you're working with significant figures, it won't limit them. Feet to Inches Example Let's say you measure a room and find it is 12.2 feet across. Find the number in inches. length in inches = length in feet x 12length = 12.2 ft x 12length = 146.4 or 146 inches Converting Inches to Feet Since all you do is multiply by 12 to convert feet to inches, it should make sense to you that all you do to convert inches to feet is divide by 12. The conversion factor is the same: 12 inches = 1 foot distance in feet = (distance in inches) / (12 inches/foot) Inches to Feet Example You measure your laptop and find the screen is 15.4 inches across. What is this in feet? distance in feet = (distance in inches) / (12 inches/foot)distance = 15.4 in / 12 in/ftdistance = 1.28 feet Important Information for Unit Conversions with Division One of the most common areas of confusion when doing unit conversions involving division concerns unit cancelling. When you're converting inches to feet, you divide by 12 in/ft. This is the same as multiplying by ft/in! It's one of those rules you use when multiplying fractions that a lot of people forget about when dealing with units. When you divide by a fraction, the denominator (part on the bottom) moves to the top, while the numerator (part on the top) moves to the bottom. Thus, the units cancel out to give you the desired answer.