Timber Cladding Calculator UK 2026 — How Much Cladding Do I Need?

Use our free timber cladding calculator

How to Calculate Timber Cladding Quantity UK — Step by Step

Timber cladding profiles — each profile has a different effective coverage width, which is what determines how many linear metres of board are needed per m² of wall area. The face width is not the same as the board width — the rebate, overlap, or gap reduces the effective coverage of each board.

If you prefer to calculate manually — or want to understand how the calculator above works — here is the step-by-step method for calculating timber cladding quantity in the UK:

1. Calculate total wall area (m²): Measure the height and width of each elevation in metres. Multiply height x width to get the gross area. Add all elevations together for the total gross area
2. Deduct openings: Subtract the area of all window and door openings from the gross area. Measure each opening (height x width) and deduct. This gives the net cladding area
3. Add waste allowance: Add 10–15% to the net cladding area to allow for cutting waste, damaged boards, and board ends. This gives the order area
4. Divide by effective board coverage: Divide the order area by the effective coverage width of your chosen profile (in metres) to get the total linear metres of board required. See the coverage table below for each profile
5. Convert to number of boards: Divide total linear metres by the board length available (typically 3.0m, 4.2m, or 4.8m). Round up to the nearest whole board

Timber Cladding Coverage UK — Boards Per m² by Profile

Timber Cladding Calculation Examples UK

Siberian larch cladding boards on pallet ready for nationwide delivery — always calculate your board quantity including waste allowance before ordering. Running short mid-installation means a second delivery and potential colour batch variation between boards from different production runs.

Example 1 — Garden room 4x4m, shadow gap 20x146mm larch

• Four elevations: 4 sides x 4m wide x 2.4m high = 4 x 9.6m² = 38.4m²
• Deduct 2 windows (each 0.9x1.2m = 1.08m²) = 38.4 – 2.16 = 36.24m²
• Add 15% waste = 36.24 x 1.15 = 41.7m²
• Divide by effective coverage 0.140m = 41.7 / 0.140 = 298 linear metres
• At 4.8m boards: 298 / 4.8 = 62.1 → 63 boards

Example 2 — House extension 6x3m rear elevation, shiplap 20x146mm larch

• One elevation: 6m wide x 2.7m high = 16.2m²
• Deduct 1 door (0.9x2.1m = 1.89m²) + 1 window (1.2x1.2m = 1.44m²) = 16.2 – 3.33 = 12.87m²
• Add 15% waste = 12.87 x 1.15 = 14.8m²
• Divide by effective coverage 0.125m = 14.8 / 0.125 = 118 linear metres
• At 4.8m boards: 118 / 4.8 = 24.6 → 25 boards

Timber Cladding Waste Allowance UK — What to Add

• 10% waste: Simple rectangular elevation with no openings — a garden room gable end, a flat featureless wall. Minimum waste allowance — only use where the elevation is genuinely straightforward
• 15% waste: Standard residential elevation with 1–3 window and door openings. The correct allowance for most house extensions, new builds, and garden rooms
• 20% waste: Complex elevation with many openings, angled cuts, or diagonal board installation. Also use 20% on rainscreen profiles where precise joint spacing creates more offcuts
• Never order to exact area: Running short mid-installation means waiting for a new delivery and risking colour batch variation between boards from different production runs. The cost of the extra boards is always less than the cost of a second delivery and potential colour mismatch

What Else Do I Need to Order? — Batten System and Fixings

Siberian larch cladding boards close up — ordering the right quantity of boards is only part of the equation. A correctly installed cladding system also requires breather membrane, treated softwood battens, A4 stainless steel fixings, and corner posts and reveal boards for junction details.

Natural timber cladding grain — the board supply is only part of what needs to be ordered for a complete cladding installation. Breather membrane, treated softwood battens, A4 stainless fixings, corner posts, and reveal boards all need to be included in your order.

Boards are only part of what needs to be ordered for a cladding project. The complete system requires:

• Breather membrane: Allow total wall area plus 10% for overlaps — available in standard 50m rolls
• Counter battens (25x38mm): At 600mm centres across the wall width — total wall height x number of batten runs. Allow 10% extra for waste and cutting
• Support battens (25x50mm): At 600mm vertical centres — total wall width x number of courses. Allow 10% extra
• A4 stainless steel screws: Allow 2 screws per board per batten crossing for boards 140mm+ wide. See our PFS+ C2 A4 stainless fixings
• Corner posts: One 45x45mm larch corner post per external corner — length = wall height plus 50mm
• Reveal boards: One reveal board per window and door opening — perimeter of each opening plus 10%
• Hidden fix clips (rainscreen only): Tiga 100-piece pack per 8–10m² of rainscreen cladding

See our full installation guide for the complete specification and our fixings guide for fixing quantities and spacing.

Timber cladding on a completed house exterior — knowing your exact board quantity and supply cost before ordering avoids under-ordering mid-project and unnecessary over-spend. Use the cost table below to estimate your project cost using real 2026 prices direct from our shop.

Timber Cladding Cost Calculator UK — Real 2026 Prices (ex VAT)

All prices are ex VAT, supply only — boards at calculated quantity including 15% waste. Prices taken directly from our online shop. See our timber cladding cost per m² guide and our how much does it cost to clad a house guide for full supply-and-install pricing including batten system, membrane, fixings, and labour.