Wood Weight Calculator UK: Timber Density, Weight Per Metre and Structural Sizes
UK timber weight is calculated as Weight (kg) = Width (m) x Depth (m) x Length (m) x Density (kg/m3) — enter your dimensions in millimetres and metres, choose a species or structural grade (C16/C24), and get an instant weight in kilograms, useful for van payload checks, joist load calculations, or simply working out how much a delivery will weigh.
Quick Answer
UK timber weight is calculated as Weight (kg) = Width (m) x Depth (m) x Length (m) x Density (kg/m3) — enter your dimensions in millimetres and metres, choose a species or structural grade (C16/C24), and get an instant weight in kilograms, useful for van payload checks, joist load calculations, or simply working out how much a delivery will weigh.
Wood Weight Calculator UK: Timber Density, Weight Per Metre and Structural Sizes
Enter your values below for an instant result, then see the formula, worked example, and common mistakes.
Enter your timber dimensions in metres/millimetres, then click calculate.
How to Use This Calculator
UK softwoods (Scandinavian redwood/pine, spruce/whitewood, Douglas fir) generally range 370-530 kg/m3 kiln-dried; UK hardwoods (European oak, beech, ash) generally run 580-760+ kg/m3. C16 and C24 are structural strength grades with their own TRADA-published mean densities (370 and 420 kg/m3 respectively).
Common UK timber lengths are sold in 0.3 m increments, commonly 2.4, 3.0, 3.6, 4.2, and 4.8 m.
UK carcassing sizes are typically specified as e.g. 47×100, 47×150, or 47×225 mm; joinery/PAR timber uses smaller finished sections like 25×50 or 50×100 mm.
Kiln-dried timber at roughly 15% moisture content (MC) is the standard reference condition for UK density tables and most purchased sawn timber. Green (freshly felled, unseasoned) timber can weigh 30-60% more due to retained water.
Multiply by quantity to check a full timber pack’s weight against a van’s payload rating or to plan a delivery.
Formula
Weight (kg) = Width (m) x Depth (m) x Length (m) x Density (kg/m3). UK timber sizes are specified in millimetres, so divide width and depth by 1,000 before multiplying. For structural carcassing timber, C16 and C24 refer to strength grades (not species) with published mean densities of 370 kg/m3 and 420 kg/m3 respectively (TRADA, kiln-dried regularised timber).
Reference Table: UK Timber Density by Species/Grade
| Species/Grade | Density (kg/m3) | Type | Typical UK use |
|---|---|---|---|
| Western Red Cedar | 370 | Softwood | Cladding, garden buildings |
| C16 (structural grade) | 370 | Softwood grade | Stud walls, general carcassing |
| Spruce/Whitewood | 450 | Softwood | Joinery, carcassing |
| C24 (structural grade) | 420 | Softwood grade | Floor joists, rafters (higher strength) |
| Scandinavian Redwood (Pine) | 510 | Softwood | Structural, joinery, flooring |
| Douglas Fir | 530 | Softwood | Structural beams, decking |
| European Larch | 590 | Softwood | Cladding, decking, fencing |
| Black Walnut (American) | 640 | Hardwood | Furniture, veneer |
| European Oak (joinery grade) | 720 | Hardwood | Flooring, beams, furniture |
| American White Oak | 760 | Hardwood | Flooring, furniture, barrels |
| Balau | 845 | Hardwood | Decking, heavy outdoor use |
Common Mistakes to Avoid
- Confusing C16/C24 (strength grades) with a species — they describe structural strength classification for graded softwood, most commonly Scandinavian redwood or European spruce, not a specific timber species.
- Using nominal (sawn) size instead of actual finished size for PAR (planed all round) joinery timber — sawn 50×100 mm typically finishes closer to 45×95 mm after planing, which reduces the true weight slightly.
- Applying kiln-dried density values to green (unseasoned) timber — green timber, especially hardwood, can weigh 30-60% more due to retained moisture, which matters for both transport payload and structural dead-load calculations before the timber has dried in place.
- Ignoring pack weight limits when ordering structural timber for delivery or self-collection — multiply per-metre weight by quantity and length, and check against your vehicle’s payload before loading a full pack.
When the Estimate May Be Wrong
Density figures represent typical values for kiln-dried timber at approximately 15% moisture content, the standard condition for purchased UK sawn timber, and can vary by growth region, individual board density, and specific mill/supplier. For structural design (joist sizing, beam spans), always use the specific grade stamp, span tables, or a structural engineer’s calculation rather than average species density alone.
FAQs
How do you calculate timber weight in the UK?
Multiply width in metres by depth in metres by length in metres by the timber’s density in kg per cubic metre — since UK timber dimensions are given in millimetres, divide each by 1,000 first.
What is the difference between C16 and C24 timber?
C16 and C24 are UK structural strength grades for softwood timber, not species — C24 is the higher-strength grade with a higher mean density (420 kg/m3) compared to C16 (370 kg/m3), used where greater structural performance is required, such as longer floor joist spans.
How much does a pack of timber joists weigh?
Multiply the per-metre weight (from width, depth, and density) by the joist length and then by the number of joists in the pack — for example, 50 joists of 47x150mm C16 at 4.8m each weigh roughly 626 kg total.
Does moisture content affect timber weight significantly?
Yes — green (unseasoned) timber can weigh 30 to 60% more than the same timber once kiln-dried to the standard 15% moisture content used in most UK density reference tables.
Sources and Methodology
UK timber species density table and C16/C24 structural grade mean densities (370 kg/m3 and 420 kg/m3, kiln-dried regularised timber) sourced from the Wooduchoose UK timber density database and TRADA (Timber Research and Development Association) structural grade reference values, consistent with standard UK construction industry timber weight guidance.
