Free tool
Timber Cladding Calculator
Enter your wall sizes, take off windows and doors, and choose a board. The calculator works out the linear metres, number of boards, battens, fixings and an indicative cost from our project price list.
Calculate your cladding
How to calculate timber cladding
- Measure each wall and multiply width by height. For a gable, multiply the base width by the peak height and halve it.
- Take off openings such as windows and doors to get the net area in m².
- Find the effective cover of your board: the width it covers once fixed. Add the gap if you are leaving open joints.
- Convert to linear metres: 1,000 ÷ cover (mm) = linear metres per m². Multiply by the net area.
- Add waste: usually 10%, or 15% with lots of openings, corners or gables.
- Count boards by dividing the total linear metres by your board length, and measure corners, reveals and trims separately.
Worked example
A 6 × 2.5m wall with one 1.2 × 1.2m window has a net area of 15 − 1.44 = 13.56 m². Clad in our TF38 Channel Shadow Gap (125mm cover), that is 1,000 ÷ 125 = 8 linear metres per m², so 108.5 lm, or 119.3 lm with 10% waste: about 29 boards at 4.2m.
Linear metres per m² by profile
Cover for our standard TF profiles. Finished sizes vary slightly by species, so the calculator uses the cover for the exact product you choose.
| Profile | Nominal size | Cover | Linear metres per m² |
|---|---|---|---|
| TF15 Screen Slat / Batten (rounded edges) | 25x50mm | 38mm | 26.32 |
| TF32 Batten (rounded edges) | 50x50mm | 45mm | 22.22 |
| TF27 UTK Narrow Secret Fix | 32x80mm | 53mm | 18.87 |
| TF29 Narrow Rainscreen Rhombus | 32x75mm | 60mm | 16.67 |
| TF79 Tongue & Groove V-Joint | 25x100mm | 84mm | 11.90 |
| TF9 Loglap (redwood only) | 25x100mm | 85mm | 11.76 |
| TF7 Slim Shiplap | 16x125mm | 103mm | 9.71 |
| TF28 Internal Multi-Groove Panelling | 19x120mm | 110mm | 9.09 |
| TF104 Slim Tongue & Groove V | 16x125mm | 114mm | 8.77 |
| TF41 Charred Channel | 25x150mm | 120mm | 8.33 |
| TF67 Double Channel | 25x150mm | 120mm | 8.33 |
| TF6 Twin Channel | 25x150mm | 125mm | 8.00 |
| TF38 Channel Shadow Gap | 25x150mm | 125mm | 8.00 |
| TF52 Viking Secret Fix | 25x150mm | 125mm | 8.00 |
| TF1 T&G V-Joint Large V | 25x150mm | 134mm | 7.46 |
| TF5 Wide Rainscreen Rhombus | 25x150mm | 134mm | 7.46 |
| TF30 T&G Small V | 25x150mm | 134mm | 7.46 |
| TF46 Shiplap – Ogee Scallop | 25x150mm | 134mm | 7.46 |
| TF19 Premium Rebated Featheredge | 32x175mm | 135mm | 7.41 |
| TF49 Charred Square Edge (eased edges) | 25x150mm | 140mm | 7.14 |
| TF11 Planed Square Edge (PSE / DAR / PAR) | 25x150mm | 145mm | 6.90 |
| TF8 Standard Featheredge 7" – 175mm | 32x175mm | 155mm | 6.45 |
| TF33 Premium Dutch Featheredge | 32x200mm | 181mm | 5.52 |
Cladding planning tips
Battens and cavity
Fix to treated (Use Class 3) battens over a breather membrane with a ventilated cavity of at least 25mm. Vertical cladding needs counter-battens so the cavity can drain.
Battens and rainscreen guidanceFixings
Use stainless steel, especially with cedar and Thermowood. Secret-fix profiles such as TF52 Viking take concealed 4.5 × 40mm screws.
Fixing guidanceFire performance
Need Euroclass B? Add fire-retardant treatment above, and check the building regulations for your project.
Building regulations guide