Lumber Weight Calculator

weight = t × w ÷ 144 × L × density × pieces board feet = nominal thickness × nominal width ÷ 12 × L × pieces linear feet = L × pieces

t

Actual thickness of one piece, in inches — 1.5 in for a 2x4, and 3.5 in for a 4x4

w

Actual width of one piece, in inches — 3.5 in for a 2x4 and 5.5 in for a 2x6

L

Length of one piece, in feet — the length you are buying, not the length you will cut

pieces

Number of pieces in the load

density

Species density in pounds per cubic foot, air-dried — the same figure in kilograms per cubic metre is the metric column of the table below

board feet

Volume in board feet, counted from nominal sizes rather than actual ones — the trade convention, so it runs above the real volume of wood

Reach for it before you lift anything: a stack of framing lumber is heavier than it looks, and the number that matters is whether one person can carry a piece, whether two can carry the bundle, and whether the trailer is already at its limit. Fill in the size you are actually buying — the actual cross-section, which is why the list says 2x4 and the arithmetic uses 1.5 by 3.5 — then the species, because that is where most of the spread is: the same 2x4 is 6.4 lb in Chinese fir and 17.5 lb in ipe. Length is the length you buy, so a 16 ft piece counts twice an 8 ft one. Read the board feet row as the invoice, not as the wood: it is counted from nominal sizes and lands about 50% above the real volume, and it is also what a supplier quotes a price per thousand against. Use it for loads, trailers, shelves and stair carries; do not use it to size a beam.

1. Ten 8 ft 2x4s in SPF

   1. Actual section: 1.5 × 3.5 = 5.25 sq in, which is 5.25 ÷ 144 = 0.03646 sq ft
   2. Volume of one piece: 0.03646 × 8 ft = 0.2917 cu ft
   3. Weight of one piece: 0.2917 × 28 lb per cu ft (SPF) = 8.17 lb
   4. Whole load: 8.17 × 10 = 81.7 lb, or 81.7 × 0.4536 = 37 kg
   5. Board feet: 2 × 4 ÷ 12 = 0.667 per foot, so 0.667 × 8 × 10 = 53.3 bf

   The defaults, and the load one person can carry in two trips. Read the two volume figures against each other: 53.3 board feet is the nominal count a yard prices at, while the wood itself is 2.917 cu ft, which is 35 board feet — the gap is the whole reason a 2x4 is not 2 in by 4 in. At 81.7 lb the bundle is one person's problem; at 40 pieces it is 327 lb and you want a cart.

2. Six 16 ft 2x12s in ipe

   1. Actual section: 1.5 × 11.25 = 16.875 sq in = 0.11719 sq ft
   2. Volume of one piece: 0.11719 × 16 = 1.875 cu ft
   3. Weight of one piece: 1.875 × 60 lb per cu ft (ipe) = 112.5 lb
   4. Whole load: 112.5 × 6 = 675 lb, or 306.2 kg
   5. Board feet: 2 × 12 ÷ 12 = 2 per foot, so 2 × 16 × 6 = 192 bf

   The heavy end of the page: six pieces, 675 lb, and each one is 112.5 lb — a two-person lift on a good day and a machine on a bad one. Ipe is 60 lb per cu ft, more than twice SPF, so this load is heavier than a dozen of the same pieces in SPF. Note that the actual width of a 2x12 is 11.25 in, not 12: everything 8 in and wider in nominal width loses 3/4 in to surfacing, where narrower stock loses 1/2 in.

3. Twenty 10 ft 2x6s in western red cedar

   1. Actual section: 1.5 × 5.5 = 8.25 sq in = 0.05729 sq ft
   2. Volume of one piece: 0.05729 × 10 = 0.5729 cu ft
   3. Weight of one piece: 0.5729 × 23 lb per cu ft (cedar) = 13.18 lb
   4. Whole load: 13.18 × 20 = 263.5 lb, or 119.5 kg
   5. Board feet: 2 × 6 ÷ 12 = 1 per foot, so 1 × 10 × 20 = 200 bf

   Cedar is the light end of the useful range — 23 lb per cu ft against SPF's 28 — which is most of why it is the decking and fence material people reach for: 20 pieces of 2x6 in cedar weigh less than 17 of them in SPF. The two 200s are a coincidence of this example and not a rule: board feet and linear feet agree only when the nominal section is exactly 12 sq in, which is true of a 2x6 and of nothing else in the list. A 2x4 would read 133 bf for the same 200 ft.

This page weighs material and does not design with it. It says nothing about whether a piece is strong enough for a beam, a joist or a header — weight and strength are different properties, and the heaviest species on this page is not the strongest one. Densities are air-dried values at about 12% moisture content, so they are a convention rather than a constant: the same species varies by up to a fifth with origin and moisture, and pressure treated lumber is heavier than the figure here because the treatment adds water and salt. The page stops at 24 ft and at solid sawn sizes, which is deliberate — beyond that you are buying engineered lumber with a different density. It does not count the weight of hardware, packaging or a pallet, and it does not know that your trailer has a tongue weight limit as well as a total one.

How much does a 2x4 weigh?

An 8 ft 2x4 in SPF is 8.2 lb, and the same piece in ipe is 17.5 lb — the species moves it by more than a factor of two. The size matters as much: that 8 ft piece is 8.2 lb, a 16 ft one is 16.3 lb, and a 2x6 of the same length is 12.8 lb because the actual width goes from 3.5 in to 5.5 in.

Why is the board feet figure higher than the wood?

Because board feet are counted from nominal sizes and the wood is measured at actual ones. A 2x4 is 0.667 board feet per foot by the trade convention, while its actual cross-section holds 0.4375 — the 53.3 board feet in the first example is 35 board feet of real wood. It is not a bug in either number: board feet are a pricing unit a yard quotes against, and nominal sizes are how the whole industry names the product.

Does pressure treated lumber weigh more?

Yes, and the page cannot tell you how much. Treatment pushes water and copper into the wood, so wet treated stock can run a third heavier than the air-dried figure here, and it dries back down over a season. Since this page multiplies a density by a volume, there is no field for it — treat the result as a floor for green treated lumber and expect the load on the day of delivery to be heavier.

Which density did you use?

Air-dried values at roughly 12% moisture content, in pounds per cubic foot: Chinese fir 22, western red cedar 23, SPF 28, Douglas fir 33, southern yellow pine 36, red oak 44 and ipe 60. These are conventions rather than constants, and every one of them varies by up to a fifth with origin and moisture — they are here to rank species against each other, not to predict a specific bundle to the pound.

Can I use this to size a beam or a joist?

No. Weight and strength are different properties, and the page only knows the first one. A species can be heavy and not particularly stiff, and the same species cut from a different part of the log behaves differently. Use a span table for the structural question; use this page to work out whether you and a friend can carry the beam to where the span table says it goes.

Why does the length stop at 24 ft?

Because solid sawn lumber stops there. Frames are milled up to 24 ft, and anything longer is engineered lumber — an LVL, a glulam or an I-joist — which is a different product with a different density and its own weight tables. Entering 30 ft here would return a number that looks plausible and is wrong.

• Wood density and specific gravity by species — the air-dried figures this page's density list is drawn from — The Wood Database
• Lumber — nominal and actual dimensions, and the board-foot convention used to price lumber — Wikipedia