Weight and Open Area Calculator
Calculate in three steps: choose the hole type, enter the hole size and pitch, then pick the material and sheet size. Open area and weight update as you type. Results are for reference only; for exact sizing and pricing we recommend contacting us.
Results
Results are theoretical reference values that ignore unperforated margins.
Results
Values are based on the approximate kg/m² figures in our standard size table.
Terms and Calculation Method
What is pitch?
Pitch (P) is the center-to-center distance between two neighboring holes. For example, with Ø5 mm holes at 8 mm pitch, 8 − 5 = 3 mm of metal (the bridge) remains between holes.
For the same hole size, a larger pitch spreads the holes out: open area decreases, the sheet gets heavier and stronger.
The metal left between two holes (the bridge) should be at least as wide as the sheet thickness; thinner bridges tear during punching. The calculator limits the dimensions accordingly.
What is row spacing (S) and when is it needed?
Oval, square, rectangular and triangular holes can have different horizontal and vertical spacing, so two values are used: P is the center distance of two holes in the same row, S is the perpendicular center distance between two rows. For round holes, S is derived from the pattern automatically.
What is the open area ratio?
It is the percentage of the sheet surface that is holes. It determines air and light permeability, filtration capacity and weight. For example, 40% open area means the perforated sheet weighs 60% of the solid sheet.
What is the difference between staggered and straight patterns?
In a staggered (60°) pattern every row is offset by half a pitch; more holes fit at the same diameter and pitch, the sheet is stronger, and it is the most common pattern. In a straight (90°) pattern holes are aligned in columns.
How is the weight calculated?
Unperforated weight (kg/m²) = thickness (mm) × density (g/cm³). Perforated weight = unperforated weight × (1 − open area). Sheet weight is this value multiplied by the sheet area (m²).
Would you like to see the sizes we keep in stock?
Browse the hole type and diameter list, grouped by sheet size and thickness, available in our warehouse.
Want to finalize your calculation?
Send us your size and material preference, and our technical team will work with you to determine the exact weight and price quote.