How much is a civil service pension worth on top of a salary (roughly)?

[Mr.B-Campag]

I'm applying for a job and would like to be able to compare it to Civil Service pay and (particularly) pension in an upcoming interview. Does anyone have an idea of what a rough equivalent salary uplift the civil service pension gives? e.g. on a £60k civil service salary would I need £65k in the private sector to be equally well remunerated (again, roughly - I know it depends on a bunch of stuff)?