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The size printed on the label at the lumber yard.
This is the size before milling — the board is actually smaller once it's surfaced and dried.
Actual lumber size
1.5 in thick x 3.5 in wide (actual)
- Actual thickness
- 1.5 in
- Actual width
- 3.5 in
They open the calculator with your figures already in it
Lumber Dimensional Size Calculator: 1.5 in thick x 3.5 in wide (actual) — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Standard North American dressed (surfaced) softwood lumber sizes, e.g. a nominal 2x4 actually measures 1.5 x 3.5 in after milling and drying
Inputs used
- Nominal Size
- 2x4
Intermediate steps
- Actual thickness
- 1.5 in
- Actual width
- 3.5 in
What this calculation does not cover
- Every figure is read straight out of a thirteen-row table, so what comes back is the standard dressed size for a nominal name rather than the board in your hand — there is no milling tolerance term anywhere in the lookup, and a piece that came off the planer a shade narrow still reads exactly 3.5 in (88.9 mm) here.
- Only the cross-section is returned: length is never asked for and appears nowhere in the answer, so nothing here tells you what stock lengths a yard runs or how many pieces a job takes.
- The width deduction is stored in each row rather than derived — nominal widths of 6 and under lose half an inch, those of 8 and up lose three quarters — so the pattern cannot be stretched to a size the menu omits, and the menu stops at 4x4 with no 5/4 decking, 3x or 6x6 entry.
- Species, grade and drying condition are not collected and change nothing in the table: a 2x8 returns 1.5 x 7.25 in (38.1 x 184.15 mm) on every path through the tool, which makes these numbers a statement about geometry alone and not about what the member can span or carry.
- A nominal name that is not one of the thirteen stored rows falls back to the 2x4 figures instead of reporting that it is unknown, so the answer is only trustworthy for a size actually picked from the list.
Add the equipment this sizes
This result is a specification — 1.5 in thick x 3.5 in wide (actual) — not a quantity. Put the thing it sizes into your project: how many, what you call it, and your supplier’s price.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-05 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Standard North American dressed (surfaced) softwood lumber sizes, e.g. a nominal 2x4 actually measures 1.5 x 3.5 in after milling and drying
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Your workspace
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