2x8 Lumber Dimensions
Deep enough to span a floor or a deck opening without a mid-support in most domestic work.
Quick specificationwhat the size actually measures
| Nominal size | 2 × 8 in (50.8 × 203.2 mm) |
|---|---|
| Actual size (dry) | 1.5 × 7.25 in (38.1 × 184.15 mm) |
| Actual size (green) | 1.5625 × 7.3125 in (39.69 × 185.74 mm) |
| Dressed section area | 10.88 in² (70.16 cm²) |
| Removed per face | 0.25 in off the thickness, 0.375 in off the width |
| Trade group | Dimensional |
Dimensionsnominal against dressed, and why they differ
The nominal figure of 2 × 8 inches describes the rough green board. After drying and planing on four faces the section measures 1.5 by 7.25 inches — that is, 0.25 inch off each of the wide faces and 0.375 inch off each edge.
Every page in this database is generated from the dressed figure, because that is the section that has to carry the load and take the fixing. If you are sizing a beam, checking a fixing length or estimating a delivery, use 1.5 × 7.25 inches (38.1 × 184.15 mm) rather than the nominal call size.
By lengthboard feet, volume and weight for each tabulated length
| Length | Board feet | Actual volume | Weight (Spruce (Sitka)) |
|---|---|---|---|
| 2x8x6 | 8 | 0.4531 ft³ | 12.16 lb |
| 2x8x8 | 10.67 | 0.6042 ft³ | 16.22 lb |
| 2x8x10 | 13.33 | 0.7552 ft³ | 20.27 lb |
| 2x8x12 | 16 | 0.9062 ft³ | 24.33 lb |
| 2x8x14 | 18.67 | 1.0573 ft³ | 28.38 lb |
| 2x8x16 | 21.33 | 1.2083 ft³ | 32.44 lb |
Two different bases, deliberately. Board feet is calculated from the nominal section, because that is the pricing convention. Volume and weight use the actual section, because that is the material actually present. A 2x4x8 is 5.33 board feet but only 0.6042 cubic feet.
Weight by speciesthe same section, every species in the database
Wood database| Species | Density | 2x8x8 weight |
|---|---|---|
| Balsa | 0.16 g/cm³ | 6.03 lb · 2.74 kg |
| Cedar (Western Red) | 0.37 g/cm³ | 13.96 lb · 6.33 kg |
| Poplar (Yellow) | 0.42 g/cm³ | 15.84 lb · 7.18 kg |
| Basswood | 0.42 g/cm³ | 15.84 lb · 7.18 kg |
| Redwood | 0.42 g/cm³ | 15.84 lb · 7.18 kg |
| Spruce (Sitka) | 0.43 g/cm³ | 16.22 lb · 7.36 kg |
| Cedar (Eastern Red) | 0.47 g/cm³ | 17.73 lb · 8.04 kg |
| Hemlock (Western) | 0.47 g/cm³ | 17.73 lb · 8.04 kg |
| Cypress (Bald) | 0.48 g/cm³ | 18.1 lb · 8.21 kg |
| Fir (Douglas) | 0.53 g/cm³ | 19.99 lb · 9.07 kg |
| Pine (Southern Yellow) | 0.55 g/cm³ | 20.74 lb · 9.41 kg |
| Mahogany (Honduran) | 0.55 g/cm³ | 20.74 lb · 9.41 kg |
| Cherry (Black) | 0.56 g/cm³ | 21.12 lb · 9.58 kg |
| Larch | 0.58 g/cm³ | 21.88 lb · 9.92 kg |
| Teak | 0.63 g/cm³ | 23.76 lb · 10.78 kg |
| OSB (Oriented Strand Board) | 0.65 g/cm³ | 24.52 lb · 11.12 kg |
| Walnut (Black) | 0.66 g/cm³ | 24.89 lb · 11.29 kg |
| Ash (White) | 0.67 g/cm³ | 25.27 lb · 11.46 kg |
| Birch Plywood | 0.68 g/cm³ | 25.65 lb · 11.63 kg |
| Birch (Yellow Birch) | 0.69 g/cm³ | 26.02 lb · 11.8 kg |
| Bamboo | 0.7 g/cm³ | 26.4 lb · 11.97 kg |
| Maple (Hard Maple) | 0.705 g/cm³ | 26.59 lb · 12.06 kg |
| Beech (American) | 0.72 g/cm³ | 27.16 lb · 12.32 kg |
| Oak | 0.75 g/cm³ | 28.29 lb · 12.83 kg |
| MDF (Medium Density Fibreboard) | 0.75 g/cm³ | 28.29 lb · 12.83 kg |
| Hickory | 0.82 g/cm³ | 30.93 lb · 14.03 kg |
| Rosewood (East Indian) | 0.85 g/cm³ | 32.06 lb · 14.54 kg |
| Ipe | 1 g/cm³ | 37.72 lb · 17.11 kg |
Weights are derived, not quoted: density at about 12% moisture content × actual volume. Treat them as a floor — green stock stays heavier until it dries.
Where it is usedtypical applications for this section
Frequently asked questionsabout 2x8
What are the actual dimensions of a 2x8?
1.5 × 7.25 inches — 38.1 × 184.15 millimetres. The nominal call size of 2 × 8 inches is the rough green section, before planing and drying.
How much does a 2x8 weigh?
That depends on the species and the length, which is why this page gives both rather than one figure. A 2x8x8 of Spruce (Sitka) weighs about 16.22 lb (7.36 kg); the table above covers every species in the database at that length.
Is a green 2x8 the same size?
No — unseasoned stock is dressed to 1.5625 × 7.3125 inches, slightly larger, because it shrinks to the dry size as it seasons. Mixing green and dry material in the same assembly will show a step once the green pieces dry.
How do I convert a 2x8 to board feet?
Multiply the nominal thickness, width and length in inches and divide by 144. For a 2x8x8 that is (2 × 8 × 96) ÷ 144 = 10.67 board feet.