Question: what is the standard size of a mason jar?
Answer: In the United States, standard-size Mason jars are made of soda-lime glass and come in two sizes: regular mouth, 2 3⁄8 in (60 mm) inner and 2 3⁄4 in (70 mm) outer diameter, and wide mouth, 3 in (76 mm) inner and 3 3⁄8 in (86 mm) outer diameter, versions.