Boards for one wall under an 8 ft ceiling, laid horizontally, using boards that cover 5 1/8" each and come in 8 ft lengths.
| Wall width | Below a 34" chair rail | Full height |
|---|---|---|
| 8 ft | 7 boards17.5 sq ft | 20 boards60.5 sq ft |
| 10 ft | 9 boards21.9 sq ft | 25 boards75.6 sq ft |
| 12 ft | 10 boards26.3 sq ft | 30 boards90.8 sq ft |
| 14 ft | 12 boards30.6 sq ft | 36 boards105.9 sq ft |
| 16 ft | 14 boards35.0 sq ft | 40 boards121.0 sq ft |
Counts reuse offcuts and include at least 10% extra, the same way the shiplap calculator counts them. Check the coverage of the boards you buy: it is the face each board adds once installed, not its full width.