Formula-Driven Civil Estimation Workbook

I need a single-file Excel workbook that lets me prepare civil work bills by entering only the basic figures while every other value populates through formulas. The sheet must support three different quantity calculations—simple Nos, L × B × D, or any other method that is tied to the chosen item—so the logic changes automatically whenever I pick an item from the drop-down list.

Key workflow
• One “Rates” sheet will hold the master list of items with their unit, default GST %, and current rate. When I select an item on the main bill sheet, its unit, rate, and the correct GST percent should flow in instantly via lookup formulas.
• On the bill sheet I will enter Nos or length, breadth, depth/height, and (if needed) a custom rate. Quantity, amount, subtotal, GST, multiple deductions, round-off, and the grand total must recalculate live.
• All calculations must rely on formulas only—no hard-coded numbers—so that any change in rates or dimensions updates every dependent cell.
• Input cells remain unlocked; every formula cell stays password-protected.
• The print area has to fit cleanly on an A4 page and contain a header with firm name, client, project, bill number, date, and space for signatures.

Deliverables
1. Excel workbook with:
– “Rates” sheet (editable)
– “Bill” sheet (protected formulas, open input cells)
2. Brief user guide outlining how to add items, modify rates, and print the finished bill.

Acceptance criteria: all calculations adapt to the measurement method selected, GST applies per item using its stored percentage, multiple deductions and round-off appear in the final total, and the layout prints neatly on one A4 page without manual adjustment.