How to estimate plumbing jobs

Plumbing requires a certain amount of knowledge and experience to be done properly. Working with plumbing fixtures, water systems and pipe may sound simple, but a mistake can be costly. A licensed plumber is necessary for certain services, such as repairing piping systems or fixtures and installing water systems. Likewise, estimating plumbing jobs is a learnt skill that is essential for the stability and growth of the plumbing company. If a plumbing job is underestimated, the plumber will lose money, and if the plumbing estimate is high, the plumbing company may not be awarded the job.

Sometimes it may be necessary to visit the job in order to determine the specific details of the task. It is possible the customer may leave out an important detail that could cost the plumber money. Make certain you take measurements while on location. It may also be a good idea to take along a digital camera to get pictures of the project.

Study any blueprints that accompany the job. Get your "take-offs" or parts and fixtures lists from the blueprints and make a list of these parts and fixtures. The blueprints will have detailed information regarding the project.

Get fixture and parts quotes from your local plumbing suppliers. It is important to get more than one quote in order to be competitive.

Determine the length of time the job will take to complete and the number of employees that will be involved. Figure driving time in your estimate if the job is a considerable distance away.

Know what your business overhead is. Many times a contractor is not aware of how much it costs to do business. Overhead includes utilities, payroll, sales tax, fuel, insurance and licensing fees. Overhead needs to be figured into the total job estimate.

Determine how much you would like to make on this job. Many plumbers try to use a 20 to 25 per cent profit margin on their jobs. Add your costs and your overhead (which includes payroll). Multiple this number by your profit margin. This is your plumbing estimate.

A formal estimate gives your company a professional image. The estimate should be typed or completed on a computer.

Make certain to include your credentials on the written estimate. This includes license and insurance information.

Leave room for acceptance signatures on the estimate. Also, give a time limit on the estimate due to fluctuating market costs.

Bid software is available to assist in the bidding process. Such software will aid the plumber in obtaining the take-offs and figuring overhead. Prices for the software vary based on the complexity and company.


Estimating is a combination of skills. Estimating requires detailed observation, accounting and imagination. There is not a perfect formula for estimating.

Things You'll Need

  • Tape measure
  • Digital camera
  • Computer
  • Calculator
  • Blueprints
  • Parts list
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About the Author

Based in Texarkana, Terri J. Morgan has been writing since 1996 when she first published a feature article in the local newspaper, "The Courier." Morgan has published feature articles in various publications as well as written copy for advertising agencies. She holds a Bachelor of Arts from Southwestern College.