Timber Calculator — Board Feet & Cost
Calculate timber volume, total length and cost for construction projects. Common size presets included.
By Konstantin Iakovlev · Founder, Calks.uk
Last updated: · Verified against HMRC and GOV.UK 2026/27 rates
Total Length
24.0m
Total Volume
0.120 m³
Per Piece
0.0120 m³
Est. Cost
£84.00
Disclaimer
This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.
How It Works
Timber in the UK is typically sold by the linear metre for structural work (joists, studwork, battens) or by cubic metre for larger quantities. Board feet (used in North America) can be converted: 1 board foot = 1/12 cubic foot = 0.00236 m³. Common structural sizes include 47 × 100 mm (C16 joists), 47 × 150 mm and 47 × 200 mm.
This calculator works with linear metres, cubic metres and board feet. Enter the cross-section dimensions and total length needed, and it converts between all three units. For stud walls, it also estimates the number of studs (typically at 400 mm or 600 mm centres) plus top and bottom plates.
UK structural timber must be graded to BS EN 14081 (C16 or C24 are the most common strength classes). For outdoor use, timber should be pressure-treated to Use Class 3 or 4. The calculator includes estimated prices per linear metre based on current UK merchant pricing.
How much timber do you need? Volume = length × width × thickness. Or in linear metres: total length needed ÷ standard length. Sample studwork wall 2.4m × 3.6m at 600mm centres: 7 vertical studs (600mm spacing across 3.6m) × 2.4m + 2 top/bottom plates 3.6m = 16.8 + 7.2 = 24m of 100×47mm CLS. Add 10-15% waste. Standard UK timber lengths: 2.4m, 3m, 3.6m, 4.2m, 4.8m, 6m. Cut waste reduces with longer lengths.
UK timber grades and species 2026. CLS (Canadian Lumber Standard): planed all sides, 38×89mm typical, used for stud walls. C16/C24: structural grades — C16 standard load-bearing; C24 stronger for joists/rafters. Pressure-treated softwood (Tanalised green): outdoor use, 15-30 year ground-contact rating. Cedar: naturally durable, weatherproof without treatment. Oak: hardwood, premium framing/feature beams. Spruce/pine: cheapest, indoor framing. Larch: outdoor cladding, durable.
UK timber prices 2026. CLS softwood 38×89mm × 2.4m: £4-£8 per length. C16 47×100mm × 3m: £8-£14. C24 47×150mm × 4.2m: £20-£35. Pressure-treated decking 32×144mm × 3.6m: £15-£25 per board. Cedar cladding £40-£80/m². Oak structural beam: £80-£200/m linear. Plywood 18mm × 2.4×1.2m sheet: £40-£70. OSB 18mm: £25-£40/sheet. Prices rose 30-50% during 2021-2022 supply crisis, stabilising 2024-2026.
Calculating studwork. Wall length / 600mm + 1 = stud count (for 600mm spacing — UK standard). Top + bottom plate = 2 × wall length. Doorways: add header (lintel) over opening + double-stud sides. Sample 4m × 2.4m partition wall: 8 studs × 2.4m + 2 plates × 4m = 27.2m of CLS. With 5% waste = ~29m. About 12 × 2.4m lengths. Insulation between studs: 100mm Rockwool (£10/m²) or PIR (£20-£25/m²).
UK timber standards and certifications. Strength-graded timber (C16, C24, etc.) per BS EN 14081. Pressure-treated to BS 8417 (use class 3 above ground; class 4 ground contact). FSC certification: ethical/sustainable sourcing — increasingly required by main UK builders' merchants (Travis Perkins, Jewson). PEFC alternative certification. Recycled timber: ReSawn UK, repurpose specialists. Building Regulations: structural calcs required for joists/rafters spanning >2.4m typically.
Example: Stud wall 3.6 m long × 2.4 m high, 47 × 100 mm at 600 mm centres
- Number of studs: 3,600 ÷ 600 + 1 = 7 studs at 2.4 m
- Top and bottom plates: 2 × 3.6 m = 7.2 m
- Total linear metres: (7 × 2.4) + 7.2 = 24.0 m
- Volume: 0.047 × 0.100 × 24.0 = 0.113 m³
Frequently Asked Questions
- What does the Timber Calculator — Board Feet & Cost do?
- Calculate timber volume, total length and cost for construction projects. Common size presets included.
- Does this include waste allowance?
- Yes. Most building material calculations include a standard 10% waste allowance. You can adjust this figure depending on the complexity of your project and cutting requirements.
- Are prices accurate?
- Material prices are indicative estimates based on average UK prices. Actual costs vary by region, supplier, brand and current market conditions. Always get quotes from local suppliers.