MAC pigment amount vs. others

[SkylarV217]

This may sound stupid, But MAC has 7.5 grams in a jar and its a ton , but others like MAD and About face say they have 5g.... but it doesn't look like its anywhere close to the amount in a MAC jar .... Why is this ?

 

[jenjunsan]

It's by weight. So, if it is finer, it weighs more but takes up less space. (I think )