Calculation of when to payback mortgage in lump sums

[dogpash]

Hi Guys

For the moment assuming I always want to pay back my mortgage ASAP whenever I have free cash to do so.

I want to calculate when financially it is best to pay back (what is the minimum amount that is worth it). So something that takes into account my % interest rate, outstanding amount and the penalty for early repayment.
Anyone able to point me to such an equation?

Thank you

[waltworks]

You have a prepayment penalty? Really? I haven't heard of anyone having one of those in at least a decade.

Your answer (setting aside the penalty thing) is easy, though. If your goal is to pay off the mortgage as fast as possible, putting money (in any amount) in as soon as you have it is the fastest way to do it.

-W