When will my house be paid off if I pay extra?

how can i figgure out when my house will be paid off if i were to base it on the real payment. i should be paying 700 per month but i pay from 850 to 1200 depending on my pay check

Not sure you are asking the question you to which you want the answer.  If you only make your normal house payment of $700 per month, the home would be paid off at the end of the term of the mortgage (30 yr, 15 yr, etc.).

If the real question your asking is when would your home be paid off taking in the effect of your additional principal payments, there are a number of mortgage calculators online where you can plug in the information and determine when the mortgage is satisfied.

unknown, here is a link to bloomberg's mortgage calculator, put in your current mortgage terms, and then enter your monthly principal pre-payments.  You can even print out a amorization report.

http://www.bloomberg.com/invest/calculators/mortgage.html