Calculators
Siding Calculator
Estimate siding panels and boxes to buy from wall size, panel size, and waste allowance locally in your browser.
Enter the wall size and a single siding panel size in feet to estimate how many panels to buy, including a waste allowance for cuts, openings, and breakage. The calculation runs locally in your browser; your values are not uploaded or stored.
Enter panel dimensions in the same unit as the wall; for example, a 12 ft panel with 8 inch exposure is about 12 by 0.67 ft. This estimate covers one wall face and ignores doors, windows, gables, trim, and overlap, so measure each face separately and add extra waste when openings matter. Check your supplier because panel sizes and box counts vary by product. This siding estimate is a planning guide, not a purchase guarantee.
Find how many siding panels to buy without uploading anything.
Enter the wall length and height plus a single siding panel length and width, an optional panels-per-box count, and a waste allowance to see the wall area, panel count, and rounded-up box count. Everything runs locally in your browser, so your values are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What does the siding calculator show?
Enter the wall length and height, a single siding panel length and width in the same unit, an optional panels-per-box count, and a waste allowance. The calculator returns the wall area, the panel area, and the panel count with waste rounded up, plus the box count when panels per box is given, with the calculation shown. For example, a 30 by 8 ft wall with 12 by 0.67 ft panels and 10% waste needs about 33 panels, so buy 2 boxes at 20 panels per box.
Which formula does the siding calculator use?
It uses wall area = wall length x wall height, panel area = panel length x panel width, then panels = wall area / panel area x (1 + waste percent / 100) rounded up, and boxes = panels / panels per box rounded up. Use the same length unit for the wall and the panel; for example, a 12 ft panel with 8 inch exposure is about 12 by 0.67 ft. The estimate covers one wall face and ignores doors, windows, gables, trim, and overlap, so measure each face separately.
Which inputs are accepted?
Enter a wall length, wall height, panel length, and panel width greater than zero through 1000000000, an optional panels-per-box whole number from 1 to 1000000000, and a waste allowance from 0 to 100 percent (blank means 10). Decimal sizes are accepted. Zero sizes, negative numbers, non-numeric text, and values outside these limits show a clear error instead of a result.
Do my numbers stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.