Walk through your home and make a list of every plumbing job that needs completed. If you have a leaky pipe, for example, write down the exact dimensions of the pipe that needs to be replaced and write down the material it is made from.
Continue through your home, recording all necessary plumbing jobs along the way.
Get prices for all the necessary parts you need. If you know you need a 6-inch copper pipe, for example, go to the hardware store and find out how much that pipe will cost. Continue to do this for the rest of the parts on your list. Add up all the totals for a rough estimate of how much plumbing will cost you (if you are completing the job yourself).
Find out the hourly rate for local plumbers in your area (for hourly work). These totals will commonly be found on the plumber's website or by giving the service a call. Detail the type of work you need completed to see if the plumber can give you an estimate of how many hours a job of your size is likely to take. Multiply the cost per hour by the number of hours and add to that the cost of your parts to find an estimate of how much the plumbing work will cost.
Find out a plumber's flat rate fee (if applicable). Certain plumbers don't charge by the hour and simply charge by the job. In this event, take the cost of the plumber and add to that the cost of parts to find an estimate of how much the job will cost.