A relative atomic mass (also called atomic weight; symbol: "A") is a measure of how heavy atoms are. It is the ratio of the average mass per atom of an element from a given sample to 1/12 the mass of a carbon-12 atom. In other words, a relative atomic mass tells you the number of times an average atom of an element from a given sample is heavier than one-twelfth of an atom of carbon-12. The word "relative" in relative atomic mass refers to this scaling relative to carbon-12. Relative atomic mass values are ratios; relative atomic mass is a dimensionless quantity. Relative atomic mass is the same as "atomic weight", which is the older term.