perforated metal open area calculation

Formulas for Determining Percentage of Open Area

In each formula “D” = hole diameter and “C” = center spacing

Round Hole Staggered Pattern (60°)

Dia ²
Center ²
x
90.5
=
Percentage of Open Area

Round Hole Staggered

Round Hole Straight
Line Pattern (90°)

Dia ²
Center ²
x
78.54
=
Percentage of Open Area

Round Hole Straight

Round Hole Diagonal
Pattern (45°)

Dia ²
Center ²
x
78.54
=
Percentage of Open Area

Round Hole Diagonal