1. Measure the finished blank
Enter the actual rectangular sheet width and length, including any non-perforated edges. The four margins are measured to the nearest hole perimeter, not its centre.
Engineering Tool · Perforated Sheet
Estimate the number of full round holes on a rectangular sheet from its finished dimensions, blank edge margins and centre-to-centre pitch. Compare straight rows with a 60° staggered layout.
Margin definition: each blank margin is the clear distance from the finished sheet edge to the nearest hole edge. Use actual sheet dimensions and the same unit throughout.
Only complete holes that fit inside the defined margins are counted.
Whole holes and complete rows only; no partial holes.
Schematic only. Drawing scale, edge centering and manufacturing tolerances are not represented.
Columns = floor((W − left − right − D) / Cx) + 1; rows = floor((L − top − bottom − D) / Cy) + 1.
Floor means round down to a whole number. The first hole edge starts at the entered left and top margins. Remaining space may be larger on the right or bottom.
Enter the actual rectangular sheet width and length, including any non-perforated edges. The four margins are measured to the nearest hole perimeter, not its centre.
Use straight rows with independent horizontal and vertical pitches, or a 60° round-hole stagger with vertical pitch equal to 0.866025 × horizontal pitch.
This is an anchored layout estimate. A centred pattern, shifted stagger phase, weld strip, clamps or a different edge rule can change the actual hole count.
Measure from the finished sheet edge to the nearest edge of a complete hole. If your drawing specifies the distance to a hole centre, subtract half the hole diameter before entering the margin.
The estimate anchors the first hole at the left and top margins and rounds down to full holes. A centred layout, a shifted stagger phase, clamping zones, weld strips and manufacturing tolerances can change the final count.
For equal centre spacing Cx in a triangular pattern, the vertical distance between rows is Cx × √3 / 2, approximately 0.866025 × Cx. Every second row begins half a horizontal pitch to the right.
No. Only round holes that fit wholly inside the entered four margins are counted. Edge-trimmed holes require an approved layout drawing.
No. The current count model covers full circular holes in straight or 60° staggered rows. For pattern open-area percentages across other shapes, use the Perforated Metal Open Area Calculator.
No. The four edge margins are included, but an internal weld strip is not. Divide the sheet into perforated regions or confirm the final count from the manufacturing drawing.
Send us the sheet drawing, hole diameter, pitch, margins, thickness and material for a manufacturing review.
Contact Our EngineersEngineering note: This tool counts ideal full circular holes in a flat rectangular sheet. It does not generate a shop drawing or account for partial edge holes, tooling constraints, tolerances, forming, welds or irregular boundaries. Confirm the final layout with an approved drawing.
Products
Resources
Contact us
Location:
Hi-Tech Industrial Zone, Hengshui,
Hebei, China, 053000
Contact:
+86 133 1308 7837
Email: info@alloyfilter.com
COPYRIGHT © 2022 FILTALLOY TECHNOLOGY LIMITED
