Lumber Calculator

Calculate studs and lumber for framing projects

Project Details
Enter your measurements and requirements
Results
Calculated estimates for your project
Wall Dimensions0' x 0'
Studs Needed1
Plates (2x4)0
Est. Board Feet0

Additional Information

About This Lumber Calculator

Our lumber calculator helps you determine how many studs and plates you need for framing walls. Whether you're building an interior partition or framing an addition, this tool calculates the number of studs based on your wall length and standard on-center spacing.

The calculator accounts for top and bottom plates (the horizontal members that studs attach to) and includes end studs. It also provides an estimate of total board feet to help you compare prices between suppliers who may price lumber differently.

This tool is perfect for DIY homeowners planning framing projects, contractors preparing material lists, and anyone asking "how many studs do I need for a 20-foot wall?" Remember to add extra studs for corners, door/window king studs, and cripple studs.

How to Use This Calculator

Follow these steps to calculate your lumber needs:

  1. Enter the total length of the wall in feet
  2. Enter the wall height (typically 8, 9, or 10 feet)
  3. Specify stud spacing (16" on center is standard for most walls)
  4. Review the number of studs and plates needed
  5. Add extra for corners, openings, and waste
Frequently Asked Questions

How many studs do I need for a 10-foot wall?

For a 10-foot wall with 16-inch on-center spacing, you need 9 studs (10 feet = 120 inches / 16 = 7.5, round up to 8, plus one starter = 9 studs). Add extra studs for corners (3 per corner), door openings (2 king studs + 2 jack studs per door), and window openings.

Should I use 16-inch or 24-inch stud spacing?

Use 16-inch on-center for exterior walls, load-bearing walls, and walls that will have tile or heavy finishes. Use 24-inch on-center for non-load-bearing interior walls to save material. Some building codes require 16-inch spacing for all walls. Always check local codes.

What is a board foot?

A board foot is a volume measurement: 1 foot x 1 foot x 1 inch (144 cubic inches). A standard 2x4x8 contains 5.33 board feet. Board feet are used for pricing hardwoods and specialty lumber. Calculate board feet as: (thickness x width x length) / 144, using actual dimensions in inches.

What's the difference between 2x4 and 2x6 walls?

2x4 walls (3.5" actual) are standard for interior walls and many homes. 2x6 walls (5.5" actual) allow more insulation, are stronger for load-bearing applications, and are required by some energy codes for exterior walls. 2x6 walls cost about 20% more in materials.

How much lumber do I need for door and window openings?

Each door needs: 2 king studs (full height), 2 jack studs (to support header), and a header. Each window needs the same plus a sill and cripple studs below. For rough planning, add 5-7 studs per door and 8-10 per window to your calculated amount.

Should I use pressure-treated lumber for framing?

Use pressure-treated lumber only for bottom plates that contact concrete (sill plates on foundations). Regular framing should use standard kiln-dried lumber which is straighter and easier to work with. Some codes require fire-treated lumber for certain applications.

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