Door Header Size Calculator Pro (USA)
Estimate the correct header dimensions for your door or window opening according to standard building codes.
Why Use a Door Header Calculator?
Installing a door header that is too weak can lead to sagging walls, stuck doors, and structural failure. Our Door Header Size Calculator Pro (USA) simplifies the complex engineering tables from the International Residential Code (IRC) into a simple, easy-to-use tool for contractors and DIYers.
What is a Header?
A header is a horizontal beam that sits above a door or window opening. Its primary job is to carry the load of the structure (roof, floors, walls) above the opening and transfer it to the vertical studs (king and jack studs) on either side.
Understanding the Loads
- Dead Load: The permanent weight of the structure (materials, roofing, drywall).
- Live Load: Temporary weight such as snow, people, or furniture.
- Tributary Width: The portion of the roof or floor that the header actually supports. This tool calculates this automatically based on your building width.
How is the Size Calculated?
This calculator assumes standard framing practices. It determines the required size based on:
- The span (width of the opening).
- The building width (to calculate tributary load).
- The number of floors supported.
- The wood species strength (different woods have different load-bearing capacities).
Reset password
Enter your email address and we will send you a link to change your password.
