窗户过梁尺寸计算器 — 公式

## How to Size a Window or Door Header

### General Rules of Thumb

For load-bearing walls, header depth increases with span:

- Up to 4 ft span: 2x6 header (or doubled)
- 4-6 ft span: 2x8 header
- 6-8 ft span: 2x10 header
- 8+ ft span: 2x12 header or engineered lumber (LVL)

Add 2 inches of depth for each additional floor supported above the opening. Non-bearing walls typically need only a flat 2x4 header for plate support.

### Important Note

This calculator provides general guidelines. Always consult local building codes and an engineer for final header sizing, especially for spans over 8 feet or multi-story loads.