Estimating size of sql server and tables

Hi we are trying to estimate the size of a sql server database so our admins can advise us of the size.

We would rather have the upper limit.

So we know number of rows - and the columns.

So I appreciate for the general table sizes it would be the maximum size the column could hold.

However we need something for indexs. ball park is fine.

If column ID was index..if I just doubled the size of column ID would that suffice? will the index size ever be larger than then the size of the column we are indexing?? if so I will use this as a guideline.

You can calculate the size of the index using the description here. It is perhaps more detailed than what you are looking for. If that is the case, just calculate the space needed for leaf level nodes and add some percentage to it.

a leaf node would always be less space than the column indexed? so my theory stands?

Quite the opposite! A leaf level node will need more space than the column(s) being indexed.