Count clear cells, not continuous boards
Rows and columns count clear openings. Perimeter members and internal divisions occupy part of the grid footprint. Subtract the margins first, then account for all member faces before dividing the remaining width and height.
A regular grid need not have square cells. Check the two clear dimensions separately. The 4×3 example below has rectangular cells and retains that name throughout its drawing and template.
Clear cell width
(wall width − 2 × side margin − (columns + 1) × vertical face) ÷ columnsClear cell height
(wall height − 2 × vertical margin − (rows + 1) × horizontal face) ÷ rowsWorked layout
4 × 3 grid accent wall
Example measurements
- Wall
- 120 × 96 in
- Member face
- 3 in
- Grid
- 4 columns × 3 rows
- Joints
- Vertical through, horizontal butt
Layout result
- Grid
- 4 columns × 3 rows
- Clear cell width
- 2 ft 2 1/4 in
- Clear cell height
- 2 ft 4 in
Compare on the same wall
Only the named layout setting changes. Wall measurements stay the same.
Vertical members through
2 ft 2 1/4 in clear width / gap · 21 pieces on Wall A
Try this variation →Horizontal members through
2 ft 2 1/4 in clear width / gap · 19 pieces on Wall A
Try this variation →Square cells with equal top/bottom margins
2 ft 2 1/4 in clear width / gap · 21 pieces on Wall A
Try this variation →Make exact squares by changing a permitted boundary
Choose Exact squares when equal clear width and height is a requirement. If the current wall, counts, and faces cannot close to that shape, review the suggested margin or count changes. The wall measurement remains the measured wall; a square constraint should not silently stretch it.
Decide which edges may move before applying a suggestion. A centered inset can use margins, while a field required to touch casing and an existing rail has fewer choices. Review the resulting footprint at those actual stops.
Choose the direction that runs through each crossing
Vertical-through construction keeps vertical members continuous and fits horizontal pieces between them. Horizontal-through does the reverse. Their front views can occupy the same grid lines while their cut-piece counts and lengths differ.
Measure the actual faces in both directions and inspect a central crossing and perimeter junction. Do not count both directions as full-length boards on one face plane for a butt-jointed layout. A half-lap or layered assembly needs its own machining detail.
Keep alignment while inspecting interrupted pieces
Locate the finished opening from the same wall zero. An opening can interrupt the pieces without moving the whole grid, leaving narrow cells or short fragments beside casing. Check those conditions at their real position.
If the focal object or casing makes the pattern awkward, compare whole-grid counts or margins before moving one member locally. Every local shift changes the adjacent clear cells.
Match the material plan to the chosen joints
Assign compatible profiles, stock, kerf, end trim, and spares. Inspect long through members separately from the short pieces that butt between them. Orientation alone does not establish whether profiles can share a purchase group.
Test one intersection with real material. Diagonal, curved, free-form, structural, and unmodelled layered joints are outside this regular face layout. Confirm backing, fastening, and corner fit at the installation location.
Accent Wall Calculator questions
Does a 4×3 grid have square cells?
Not necessarily. This example has rectangular clear cells. Exact squares require matching clear width and height.
Why do the joint options change the cut list?
The through direction determines which members remain continuous and which pieces fit between them.
Will an impossible square layout change the wall size?
No. Review the conflict and choose an acceptable margin or count change without altering the physical survey.