Why 1ml is equal to 1cm3?

You know that volume is equal to the space created.The term cubic centimeter is 1cm long and 1cm high.One milliliter (mL) is the equivalent volume of a cubic centimeter. Therefore the term mL is preferred over centimeter cube.

Also we can obtain it from the relation,

1 litre = 1000 cm³

and also 1 litre=1000mL

Then 1000mL=1000 cm³

or 1 cm³ = 1 mL