Coordinates for a grid or row of holes
Mounting plates, gusset patterns, perforated brackets, fastener grids — most hole layouts are a rectangular grid or a straight row at some angle. This calculator turns the count and pitch into the X and Y position of every hole, ready to mark out, drill, or drop into a CNC program.
How it works
For a grid, holes step across by the X pitch and up by the Y pitch, so column c and row r sit at X = origin X + c x (X pitch), Y = origin Y + r x (Y pitch). For a linear pattern, each hole is one pitch further along a line set at your chosen angle: X = origin X + i x pitch x cos(angle), Y = origin Y + i x pitch x sin(angle).
Pattern extent
The extent is the overall footprint: for a grid it is (columns – 1) x X pitch wide by (rows – 1) x Y pitch tall; for a line it is (holes – 1) x pitch long. Use it to check the pattern fits the stock before you cut.
Related layout tools
For holes arranged around a circle, use the bolt circle calculator. To turn a single distance and angle into X and Y, see the polar coordinate calculator.
Worked example
A 3-column by 2-row grid on 1 in centers from origin 0,0 gives six holes spanning 2 in by 1 in: the bottom row at (0,0), (1,0), (2,0) and the top row at (0,1), (1,1), (2,1).
FAQ
Can I offset the whole pattern?
Yes — set origin X and origin Y to your datum and every coordinate shifts with it, so you can work straight from machine zero or a corner of the part.
What angle does a linear pattern use?
Zero degrees runs the row along the X axis; 90 degrees runs it straight up the Y axis. Any angle in between tilts the row, which is handy for diagonal bolt rows.