Science, Tech, Math › Science Converting Millimeters to Centimeters Worked unit conversion example problem Share Flipboard Email Print Larry Washburn/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 February 07, 2019 This example problem demonstrates how to convert millimeters to centimeters, which is actually much easier than you may have thought. The Problem Express 312 millimeters in centimeters. In order to calculate this problem, you'll need to know how many millimeters make up a single centimeter. The following is the equation for centimeters to millimeters: 1 centimeter = 10 millimeters From here, you can set up the conversion so the desired unit will be canceled out. In this case, we want cm to be the remaining unit.distance in cm = (distance in mm) x (1 cm/10 cm)distance in cm = (312/10) cmdistance in cm = 3.12 cm The Answer 312 millimeters is 3.12 centimeters.