The quick method
Multiply length by width for each rectangle in the room and add them up. Add the waste factor for your pattern, then divide by the area per box and round up.
| Pattern | Extra to buy |
|---|---|
| Straight, random stagger | 5% |
| Brick or third offset | 7–10% |
| Tiles, straight | 10% |
| Diagonal | 10–15% |
| Herringbone and chevron | 10–15% |
| Many small rooms or angled walls | Add another 5% |
The exact method
A percentage is a guess. The real waste depends on how your room width divides by the plank width, and how the room length divides by the plank length. A room 3.95 m long with 1.285 m planks wastes far less than one 4.10 m long.
The planner lays every plank virtually, reuses offcuts where they are long enough, and counts the planks actually used. It then adds a small spare margin for damaged or miscut pieces and rounds up to full boxes.
Worked example
A room of 4.00 × 3.50 m is 14 m². With 1285 × 192 mm laminate (0.247 m² per plank, 8 per box = 1.97 m² per box):
- Quick method: 14 m² + 5% = 14.7 m², divided by 1.97 = 7.5, so 8 boxes.
- Planner: lays the room with a 10 mm gap and counts 62 planks used, even after reusing offcuts. With 5% spare that is 66 planks, or 9 boxes.
The quick method would have left you one box short. In this room both the first and last rows have to be ripped to about 11 cm, and the cut-off strips cannot be reused. A plank count catches that; a percentage does not.
Keep a spare box
Production batches vary in colour. Keep one unopened box after the job for future repairs.