2×4 in cm – Actual and Nominal Dimensions
If you are working on a project that uses metric measurements, knowing the real size of a 2×4 in centimeters is important. Even though it’s called a “2×4,” the actual measurements are smaller due to the way lumber is processed.
Nominal vs. Actual Size
The term “2×4” is the nominal size, meaning the dimensions before the wood is dried and planed smooth. Once processed, the lumber’s size becomes smaller — this is the actual size.
Nominal Size: 5.08 cm × 10.16 cm
Actual Size: 3.81 cm × 8.89 cm
2×4 in cm Table
| Type | Centimeters (Actual) | Inches (Actual) |
|---|---|---|
| Standard 2×4 | 3.81 × 8.89 | 1.5 × 3.5 |
| Green / Unsurfaced 2×4 | 4.45 × 9.53 | 1.75 × 3.75 |
Why This Matters
If your build requires precision, assuming a 2×4 is exactly 5.08 cm × 10.16 cm will cause mistakes. Always measure the actual size before cutting.
Common Uses
- Framing walls in metric-based construction
- Furniture building with exact fits
- Woodworking projects with metric plans
FAQ
Why is a 2×4 not exactly 5.08 cm × 10.16 cm?
Because the nominal size refers to the board before it is dried and planed. The final, usable size is smaller.
Are 2×4 sizes the same in all countries?
No. While the U.S. and Canada are similar, other countries may have slightly different milling standards.
How can I convert inches to centimeters?
Multiply inches by 2.54. For example, 1.5 inches × 2.54 = 3.81 cm.
Final Tip
When working with metric dimensions, measure each board yourself before cutting or ordering to avoid costly errors.