How perforated sheet weight is calculated
Finished mass equals the solid sheet mass minus the mass removed by holes. A solid border increases finished weight, so the open area of the perforated field is different from the open area of the entire sheet.
L and W are the overall sheet dimensions, b is the equal border on each edge, t is thickness, and ρ is density in g/cm³. Dimensions use mm. f is the open-area fraction of the perforated field.
- Round, 60° staggered: f = π ÷ (2√3) × (d ÷ p)²
- Round, straight rows: f = π ÷ 4 × (d ÷ p)²
- Square, straight rows: f = (s ÷ p)²
d is hole diameter, s is square-hole side, and p is centre-to-centre pitch. Straight-row patterns assume the same pitch in both directions. For slots or another pattern, use the manufacturer’s field open-area percentage.
Worked example: 5 mm holes on 8 mm staggered pitch
A 2,000 × 1,000 × 1.5 mm SS 304 sheet at 7.93 g/cm³, with a 20 mm solid border and round holes on a 60° pattern, has 35.43% field open area and 33.33% whole-sheet open area. Its estimated finished weight is 15.861 kg, compared with 23.790 kg before punching.
Compare stainless steel grades for the same pattern
The example dimensions and border above are held constant. These are calculated estimates, not a stock list or a quotation.
| Material | Density g/cm³ | Estimated kg/sheet |
|---|---|---|
| SS 304 | 7.93 | 15.861 |
| SS 316 | 7.98 | 15.961 |
| SS 202 | 7.80 | 15.601 |
Questions before ordering perforated sheets
What does “open area” mean?
It is the area occupied by holes divided by the reference area. This tool reports both the perforated field percentage and the percentage across the entire sheet including solid borders.
Does the calculation include exact hole counts at the sheet edges?
No. It treats the perforated field as a repeating pattern. Partial rows, start and end margins, asymmetric borders and exact hole counts need the manufacturer’s drawing or measured sheet weight.
Can I calculate slotted or decorative perforations?
Choose “Known open area” and enter the manufacturer’s open percentage for the perforated field. The round and square formulas do not apply to decorative or slotted patterns.
What should I send for a bulk quotation?
Send the grade (for example SS 304, 316 or 202), sheet size, thickness, hole size, pitch, pattern, all margins, quantity, finish and certificate requirements. Add your delivery town, district, state and PIN code so transport and access can be reviewed.
Finished sheet weight versus chargeable blank weight
A perforated sheet estimate is the remaining metal after holes are removed. A supplier quotation may be based on the original solid blank plus punching, finishing and packing. Ask whether the rate applies to finished kg, blank kg or each sheet, and confirm any scrap allowance. Use the same basis when comparing two offers.
For multiple sizes, calculate each pattern and thickness separately, then send a line-by-line schedule with your town and delivery PIN code. Combining requirements does not confirm common stock or one dispatch.
Formula sources and review
Compiled by Steel Impex India. The geometric pattern relationships agree with the Direct Metals open-area reference. The border correction subtracts hole area only from the perforated field. See our technical reference policy for assumptions and corrections.
Related tools: solid stainless sheet weight · circle weight · ring weight · bulk buying guide for India.