Science, Tech, Math › Science Converting Ounces to Grams Share Flipboard Email Print Dave King Dorling Kindersley, 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 May 29, 2019 This worked example problem demonstrates how to convert ounces to grams. This is a common type of mass unit conversion problem. One of the most common practical reasons to know how to do this conversion is for recipes, so let's start with a food example: Ounces To Grams Problem A chocolate bar weighs 12 ounces. What is its weight in grams? Solution One of the easiest ways to solve this problem is to use the pound to kilogram conversion. If you like in a country where both units are used, this is a useful conversion to know. Start by converting ounces into pounds. Then convert the pounds into kilograms. All that remains is to move the decimal point three places to the right to convert kilograms into grams. Here are the conversions you need to know:16 oz = 1 lb1 kg = 2.2 lbs1000 g = 1 kgYou are solving for "x" numbers of grams. First, convert ounces into pounds. The next part of the solution converts pounds to kilograms, while the final section converts kilograms to grams. Note how units cancel each other out, so all you are left with is grams. x g = 12 ozx g = 12 oz x (1 lb/16 oz) x (1 kg/2.2 lb) x (1000 g/1 kg)x g = 340.1 g Answer The 12 oz chocolate bar weighs 340.1 g.