1x3 Lumber Dimensions
A general-purpose board for light framing and trim where 1x2 is too narrow to take a fixing.
Quick specificationwhat the size actually measures
| Nominal size | 1 × 3 in (25.4 × 76.2 mm) |
|---|---|
| Actual size (dry) | 0.75 × 2.5 in (19.05 × 63.5 mm) |
| Dressed section area | 1.88 in² (12.1 cm²) |
| Removed per face | 0.125 in off the thickness, 0.25 in off the width |
| Trade group | Board |
Dimensionsnominal against dressed, and why they differ
The nominal figure of 1 × 3 inches describes the rough green board. After drying and planing on four faces the section measures 0.75 by 2.5 inches — that is, 0.125 inch off each of the wide faces and 0.25 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 0.75 × 2.5 inches (19.05 × 63.5 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)) |
|---|---|---|---|
| 1x3x6 | 1.5 | 0.0781 ft³ | 2.1 lb |
| 1x3x8 | 2 | 0.1042 ft³ | 2.8 lb |
| 1x3x10 | 2.5 | 0.1302 ft³ | 3.5 lb |
| 1x3x12 | 3 | 0.1562 ft³ | 4.19 lb |
| 1x3x14 | 3.5 | 0.1823 ft³ | 4.89 lb |
| 1x3x16 | 4 | 0.2083 ft³ | 5.59 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 0.1042 cubic feet.
Weight by speciesthe same section, every species in the database
Wood database| Species | Density | 1x3x8 weight |
|---|---|---|
| Balsa | 0.16 g/cm³ | 1.04 lb · 0.47 kg |
| Cedar (Western Red) | 0.37 g/cm³ | 2.41 lb · 1.09 kg |
| Poplar (Yellow) | 0.42 g/cm³ | 2.73 lb · 1.24 kg |
| Basswood | 0.42 g/cm³ | 2.73 lb · 1.24 kg |
| Redwood | 0.42 g/cm³ | 2.73 lb · 1.24 kg |
| Spruce (Sitka) | 0.43 g/cm³ | 2.8 lb · 1.27 kg |
| Cedar (Eastern Red) | 0.47 g/cm³ | 3.06 lb · 1.39 kg |
| Hemlock (Western) | 0.47 g/cm³ | 3.06 lb · 1.39 kg |
| Cypress (Bald) | 0.48 g/cm³ | 3.12 lb · 1.42 kg |
| Fir (Douglas) | 0.53 g/cm³ | 3.45 lb · 1.56 kg |
| Pine (Southern Yellow) | 0.55 g/cm³ | 3.58 lb · 1.62 kg |
| Mahogany (Honduran) | 0.55 g/cm³ | 3.58 lb · 1.62 kg |
| Cherry (Black) | 0.56 g/cm³ | 3.64 lb · 1.65 kg |
| Larch | 0.58 g/cm³ | 3.77 lb · 1.71 kg |
| Teak | 0.63 g/cm³ | 4.1 lb · 1.86 kg |
| OSB (Oriented Strand Board) | 0.65 g/cm³ | 4.23 lb · 1.92 kg |
| Walnut (Black) | 0.66 g/cm³ | 4.29 lb · 1.95 kg |
| Ash (White) | 0.67 g/cm³ | 4.36 lb · 1.98 kg |
| Birch Plywood | 0.68 g/cm³ | 4.42 lb · 2 kg |
| Birch (Yellow Birch) | 0.69 g/cm³ | 4.49 lb · 2.04 kg |
| Bamboo | 0.7 g/cm³ | 4.55 lb · 2.06 kg |
| Maple (Hard Maple) | 0.705 g/cm³ | 4.58 lb · 2.08 kg |
| Beech (American) | 0.72 g/cm³ | 4.68 lb · 2.12 kg |
| Oak | 0.75 g/cm³ | 4.88 lb · 2.21 kg |
| MDF (Medium Density Fibreboard) | 0.75 g/cm³ | 4.88 lb · 2.21 kg |
| Hickory | 0.82 g/cm³ | 5.33 lb · 2.42 kg |
| Rosewood (East Indian) | 0.85 g/cm³ | 5.53 lb · 2.51 kg |
| Ipe | 1 g/cm³ | 6.5 lb · 2.95 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 1x3
What are the actual dimensions of a 1x3?
0.75 × 2.5 inches — 19.05 × 63.5 millimetres. The nominal call size of 1 × 3 inches is the rough green section, before planing and drying.
How much does a 1x3 weigh?
That depends on the species and the length, which is why this page gives both rather than one figure. A 1x3x8 of Spruce (Sitka) weighs about 2.8 lb (1.27 kg); the table above covers every species in the database at that length.
How do I convert a 1x3 to board feet?
Multiply the nominal thickness, width and length in inches and divide by 144. For a 1x3x8 that is (1 × 3 × 96) ÷ 144 = 2 board feet.