Board feet in an 8/4 slab, 24 in wide and 8 ft long
An 8/4 (2 in) slab averaging 24 in wide and 8 ft long is 32 board feet: 2 × 24 × 8 ÷ 12.
How to work it out
- 2 in × 24 in × 8 ft ÷ 12 = 32 bd ft per board
- 32 × 1 board = 32 board feet
For a live-edge slab, measure the width at several points and average it — the bark edge wanders, and some sellers measure the widest point instead. Ask which.
Many slab dealers price whole slabs rather than by the board foot, often at a premium for figure and width. Converting to a board-foot price is a quick way to compare two slabs of different sizes.
Adjust for your project
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- Board feet per board
- 32 board feet
- Volume (at the size entered)
- 2.667 cu ft (0.076 m³)
- Total length of boards (before waste)
- 8 ft
- Softwood construction lumber is tallied on nominal size (2×4 = 2 × 4 in), even though it measures 1½ × 3½ in. Hardwood is tallied on rough thickness (4/4 = 1 in) even after surfacing.
Board feet in a 24 in × 8 ft slab by thickness
| Thickness | Board feet per board | Volume (at the size entered) |
|---|---|---|
| 6/4 (1.5 in) | 24 board feet | 2 cu ft |
| 8/4 (2 in) | 32 board feet | 2.667 cu ft |
| 10/4 (2.5 in) | 40 board feet | 3.333 cu ft |
| 12/4 (3 in) | 48 board feet | 4 cu ft |
What to know about an 8/4 slab 24 in wide and 8 ft long
- Measure three widths, not one. Take the width at each end and in the middle, at the edge you will keep, and average them. A slab 20 in at one end and 28 in at the other is still 32 board feet if it averages 24.
- Plan on losing thickness. A 2 in slab that has cupped or twisted often flattens to 1½–1¾ in. If you need a full 1¾ in top, look at 10/4 or 12/4 stock.
- Check it is dry. Big slabs are often air-dried and can stay wet in the middle for a long time. A moisture reading close to what your room runs at — often 6–9% indoors — before you flatten it saves a top that cups later.
- It is heavy. 32 board feet of a dense hardwood is a two-person lift; the weight of a board foot of red oak gives a feel for it.
For standard 1 in stock the math is the same — see board feet in a 4/4 hardwood board, 8 in × 8 ft.
Different size? Use the full Board Foot Calculator.
What you’ll need
- Wood moisture meterMid-range price
Tells you whether lumber is dry enough to build with and firewood dry enough to burn. Readings vary by species — check the meter’s correction settings.
See options on Amazon (opens in a new tab) - Random orbit sander (5 in)Mid-range price
Leaves a swirl-free surface ready for stain or finish. Hook-and-loop discs make grit changes quick.
See options on Amazon (opens in a new tab) - 25 ft tape measureBudget price
A 25 ft tape with a stiff blade and a readable 1/16 in scale covers everything from cut lists to deck layout.
See options on Amazon (opens in a new tab)
As an Amazon Associate we earn from qualifying purchases. Links to products are affiliate links — they cost you nothing extra and help keep these calculators free.
Frequently asked questions
How many board feet is a 12/4 slab 24 in wide and 8 ft long?
At 12/4 (3 in) the same slab is 48 board feet.
How many board feet is an 8/4 slab 30 in wide and 10 ft long?
An 8/4 slab 30 in × 10 ft is 50 board feet (2 × 30 × 10 ÷ 12).
How many board feet is an 8/4 slab 20 in wide and 6 ft long?
An 8/4 slab 20 in × 6 ft — a desk or bench top — is 20 board feet.
Other common sizes
- How many board feet in a 2x4x8 — 5.33 board feet
- How many board feet in a 2x6x8 — 8 board feet
- How many board feet in a 4x4x8 — 10.67 board feet
- Board feet in a 4/4 hardwood board, 8 in × 8 ft — 5.33 bd ft (yard tally: 5)
Sources
- NIST, Voluntary Product Standard PS 20-20, American Softwood Lumber Standard (Rev. 1, 2021) (opens in a new tab) — Nominal and dressed sizes of softwood lumber; board measure on nominal size.
- American Hardwood Export Council, The Illustrated Guide to American Hardwood Lumber Grades (opens in a new tab) — Board foot, surface measure and quarter (4/4, 8/4) thicknesses under the NHLA rules.
- National Hardwood Lumber Association, Rules for the Measurement & Inspection of Hardwood & Cypress (2019) (opens in a new tab) — Paragraphs 16 and 18: board feet = surface measure × standard thickness, with standard thicknesses under 1 in measured as 1 in.