Enter your required clear span, load type, and lumber grade into the Door Header Size Calculator to get your recommended header size, along with the maximum span, load capacity, and safety factor so you know your doorway opening is properly supported.
Recommended Header Size
--
Maximum Span
--
Safety Factor
--
Load Capacity
--
A 4x6 header can typically span up to 6 feet (72 inches) for standard residential loads. The exact span depends on the lumber grade, load conditions, and local building codes.
Header size is calculated based on the span length, load requirements, and lumber specifications. Generally, the header depth should be at least 1/12th of the span length for adequate structural support.
A single 2x8 is typically not sufficient for door headers in load-bearing walls. Most applications require doubled lumber (like two 2x8s) or engineered lumber for proper load support.
For a 4-foot door opening, a 4x6 header is typically adequate for standard residential loads. However, always verify with local building codes and consider the specific load conditions.
Headers are required for door openings in load-bearing walls. Non-load-bearing walls may not require structural headers, but check local building codes for specific requirements.
Nominal sizes are the traditional names (like 2x4), while actual sizes are smaller due to drying and planing. A nominal 4x8 header actually measures 3.5" x 7.25".
Yes, engineered lumber like LVL (Laminated Veneer Lumber) or PSL (Parallel Strand Lumber) can often span longer distances than traditional lumber and may be more cost-effective for larger openings.