Measurements should always be expressed in metric, even when they are written in brackets (or the broadcast verbal equivalent of brackets) after an imperial or other system used in a direct quote or real estate story.
Exceptions are nautical miles and feet above the ground when flying.
Queensland retains “perches” to describe housing blocks, It is the only Australian state to do so; others use square metres.
You will find metric conversion tables in most good dictionaries.
Also note that 10m2 is 10m x 10m = 100 square metres.
Do not confuse square metres with metres squared.