The formula to calculate the required header size is based on the span length (L) of the door opening and the load-bearing capacity of the material. For a simple span with no overhangs, the formula can be simplified as:
L = span length of the door opening in feet
How do I calculate the header size for my door?
What factors affect the size of a door header?
Can I use this formula for any type of door?
What is the load-bearing capacity of typical wood used in headers?
How important is the header size in construction?
Can I use this calculator for a garage door?
What should I do if my calculated header size is larger than what's available?
Results are for informational purposes only and do not constitute professional advice.
