Nominal vs Actual Lumber Dimensions
What common nominal sizes actually measure once the board is dried and planed — the figures that do not change with region or code.
| Nominal size | Actual (dressed) dimensions |
|---|---|
| 1x4 | 0.75 in × 3.5 in |
| 2x4 | 1.5 in × 3.5 in |
| 2x6 | 1.5 in × 5.5 in |
| 2x8 | 1.5 in × 7.25 in |
| 4x4 | 3.5 in × 3.5 in |
Why nominal and actual differ
A 2×4 measures 1.5 in by 3.5 in. The nominal figure is the rough-sawn size before the board is dried and planed smooth on all four sides; the actual figure is what you take delivery of. Unlike an electrical rating, these do not vary with conditions, region, or code — which is why this table carries no caveat and the breaker table carries a long one.
How Varra uses it
Read directly from the engine's own source rather than transcribed, so the page cannot drift from what Varra actually answers. When a question names a nominal size, Varra puts that size in its answer's label and the matching row replaces anything it stated from memory. It is the narrow, live edge of Varra Assurance — the layer that checks work before anyone acts on it.
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