How to Calculate Building Quantities

Written by robert schrader
  • Share
  • Tweet
  • Share
  • Pin
  • Email
How to Calculate Building Quantities
No matter the structure you're building, knowing how much material you need is essential. (modern office building house construction downtown image by alma_sacra from

Making plans to build a house, or even an addition to your existing house, is an ambitious undertaking. Beyond the expertise and skill (or, if you're hiring a contractor, the expenditure) such plans require, the amount of material you will need may surprise you if you don't calculate how much of everything you'll need before you begin. Doing so will ensure construction can go on uninterrupted---in other words, you won't need to purchase additional material midway through the project---and also allow you to be more exact in your budgeting.

Skill level:

Things you need

  • Calculator
  • Tape measure

Show MoreHide


  1. 1

    Make a list of all the types of materials you'll need, without regard to quantity. If, for example, you're building a wooden shed with a metal roof, you will need wood for the walls, metal for the roof, paint for the exterior (and possibly the interior), windows, at least one door and concrete to pour a foundation.

  2. 2

    Consult your blueprints to aid you in quantifying the materials you need. If you know, for example, that your completed shed will have a footprint of 15' x 15' and you want to pour a foundation that's 10' deep, you know you will need enough concrete mix for 2,250---15 x 15 x 10---cubic feet of concrete. If you know your shed will be 10 feet high on all sides, you know you'll need at least 600 square feet---15 x 10 x 4---of wood and enough paint to cover that wood.

  3. 3

    Visit your local building materials store to find out in which quantities it sells your building materials. For example, you might find that you can buy bags of concrete that yield 150 cubic feet each, gallons of exterior paint that cover 450 square feet each and wooden panelling sold in slats that are 10 feet tall by one foot wide.

  4. 4

    Determine the amount of materials you need given the measurements you have and the capacities of your materials. If you have 600 square feet of walls and each gallon of paint covers 450, then you need 600/450, or 1.33 gallons of paint. If you believe you'll need to apply three coats of paint, however, you'll need three times this amount, or four gallons. If you need to pour 2,250 cubic feet of concrete and each bag yields 150 cubic feet, you need 2250/150, or 15 bags of concrete mix.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.