Timber Volume Calculator

Board feet, cubic volume, and weight from timber dimensions and species.

About this calculator

Board feet is the lumber industry's standard unit for pricing heavy timber, and it's a nominal-dimension volume measure, not a true cubic measure: one board foot equals a 1-inch-thick, 12-inch-wide, 1-foot-long piece, so this calculator's board-feet formula — width times depth times length, divided by 12 — treats every dimension as sawn (actual) rather than dressed size. Cubic feet and cubic meters divide by 144 instead, giving a true volume figure useful for shipping and storage estimates rather than a mill order. Weight is estimated from species-specific density at roughly 12% moisture content — air-dried, not green — which matters because green timber can weigh 30-50% more than the air-dried figures used here, so a weight estimate for freshly milled or wet timber should be treated as a floor, not a ceiling.

Species density varies more than dimension alone might suggest: Red Oak at 44 lb/ft³ weighs nearly twice as much as Western Red Cedar at 23 lb/ft³ for the identical piece of lumber, which matters for structural dead-load calculations and for crane or hand-carrying logistics on site. The order-quantity output layers a waste and trim allowance on top of the raw board-feet total to account for defect cutting, checking, and end trimming that a mill order needs to cover.

Inputs

Timber width

Timber depth

Timber length

Number of pieces

Waste / trim allowance

Wood species

Tab to move between fields

Results

Board feet per piece

64 BF

Total board feet

64 BF

Order quantity (with waste)70.4 BF

Total volume5.33 cu ft

Total volume (metric)0.15 m³

Estimated weight181 lbs

Estimated weight (metric)82.3 kg

Cross-section area64 in²

How to Use This Calculator

Enter Timber width, Timber depth, and Timber length.
Set Number of pieces, Waste / trim allowance, and Wood species.
Review Board feet per piece (BF) and Total board feet (BF).
Use Order quantity (with waste) (BF) and Total volume (cu ft) to inform your decision.

How the result changes with Timber width

Timber width	Board feet per piece	Total board feet
4	32 BF	32 BF
6	48 BF	48 BF
12	96 BF	96 BF
20	160 BF	160 BF

What each input means

Timber width: Actual width of the timber cross-section.
Timber depth: Actual depth of the timber cross-section.
Timber length: Length of each timber piece.
Number of pieces: How many identical timbers to calculate for.
Waste / trim allowance: Extra material to order for cuts, defects, and waste.
Wood species: 0 = Douglas Fir-Larch, 1 = Southern Pine, 2 = Eastern White Pine, 3 = Red Oak, 4 = Western Red Cedar.

What each result means

Board feet per piece: Board feet = (width × depth × length) / 12.
Total board feet: Board feet × number of pieces.
Order quantity (with waste): Total board feet including waste allowance.
Total volume: Total timber volume in cubic feet.
Total volume (metric): Total timber volume in cubic meters.
Estimated weight: Weight at air-dry moisture content (~12% MC).
Estimated weight (metric): Weight in kilograms.
Cross-section area: Width × depth of the timber.

How this is calculated

Worked example, using the default values

Identify Input Parameters
4 parameters
Timber width = 8, Timber depth = 8, Timber length = 12, Number of pieces = 1 = 6 input(s) provided
Calculate Board feet per piece
Board feet per piece = (widthIn * depthIn * lengthFt) / 12
64 = 64
Calculate Total board feet
Total board feet = boardFeetEach * quantity
64 = 64
Calculate Order quantity
Order quantity = totalBoardFeet * wasteMultiplier
70.4 = 70.4
Calculate Total volume
Total volume = cubicFeetEach * quantity
5.33 = 5.33

Engine last updated August 14, 2026. Checked against 2 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.

Frequently Asked Questions

Is board feet the same thing as cubic feet?

No — board feet is a lumber-industry pricing unit equal to a 1-inch by 12-inch by 1-foot piece, calculated here as width times depth times length divided by 12. Cubic feet is a true volume measure using the same dimensions divided by 144. The two track the same underlying volume but differ by a factor of 12, so don't mix them up when comparing a board-foot mill quote against a cubic-volume shipping estimate.

Why does the weight estimate assume air-dried timber?

Because the species densities used here (23-44 lb/ft³ depending on species) are standard air-dry figures at roughly 12% moisture content, the typical condition for seasoned construction lumber. Green, freshly milled timber holds far more water and can weigh 30-50% more than these figures suggest, which matters for crane picks and structural dead-load numbers on a project using unseasoned timber.

How much does species choice affect total weight?

Substantially — Red Oak at 44 lb/ft³ is nearly twice as heavy as Western Red Cedar at 23 lb/ft³ for an identical cross-section and length, and Douglas Fir-Larch, Southern Pine, and Eastern White Pine fall in between. Two timbers cut to the exact same board-foot volume can differ by close to double in actual shipping or handling weight depending on species alone.

What waste allowance should I use when ordering timber?

10% is a reasonable default for straightforward cuts with minor defects to work around. Timber graded for structural use with tighter appearance or strength requirements, or projects requiring long clear spans free of knots, often need a higher allowance since more of each piece gets rejected or trimmed away to meet grade.

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