MYnameisJames said: i truly wish i knew. im guessing length times width times height? Click to expand... That would give you a volume. If we have a N masses at discrete points what we do is take a weighted average of the position (a literal weighted average in this case): \(\displaystyle y_{cm} = \dfrac{1}{M} \sum_{i = 1}^N m_i y_i\) where M is the total mass. This is for one dimension. If you have masses at points in two dimensions then you need to do another one for the y component. To convert this to a continuous mass then you need to find the weighted average at each point using the density function, ie. \(\displaystyle y_{cm} = \dfrac{1}{M} \int \delta (y) y ~ dy \) To find the total mass you simply calculate the same thing without the extra y: \(\displaystyle M= \int \delta (y) ~ dy \) Give it a try and show us what you get. -Dan