Interior Design Costing System in Excel: Rate Card, Room Estimate, Budget vs Actual, Payment Schedule and Quotation

By Ravindra Bagale · Last updated: 17 October 2026

Download the template: interior-design-costing-system-template.xlsx: a 8-sheet system with example data and real formulas (Read me, Setup, Estimate, Site expenses, Summary, Payments, Quotation, Dashboard). Yellow cells are inputs you can type over; green cells hold formulas; blue rows are headers and totals. Replace the example data with your own and every report and the dashboard recalculate.

Made-up data: every name, amount, business and date on this page is made up for practice. Cities are used only to make the examples feel real.

1. The business story

Ruhi Interiors, Nagpur, Bagale flat 2 BHK, as of 17 October 2026 (made-up data). Contingency 5%, design fee 8%, GST 18% (inputs; confirm GST on your contract with your accountant).

₹3,06,483 has come in from the client against ₹6,12,966.

2. Build it sheet by sheet

Step 1. Setup: rate card

1. B4 contingency (5%), B5 design fee (8%), B6 GST, B7 the project name.
2. Rate card in A10:D17: Item, Unit, Material rate, Labour rate; E10 rate =C10+D10. Rooms in G10:G13.

Step 2. Estimate: room by room

1. One row per item per room: Room, Item, Qty. Pick both from drop-downs.
2. D5 unit with XLOOKUP, E5 material =C5*XLOOKUP(B5,Setup!$A$10:$A$17,Setup!$C$10:$C$17,0), F5 labour the same from column D, G5 amount =E5+F5.
3. 85 sq ft of modular kitchen at ₹1,800 comes to ₹1,53,000.

Step 3. Site expenses and Summary

1. Site expenses: Date, Room, Description, Amount, every bill against a room.
2. Summary B5 estimate =SUMIFS(Estimate!$G$5:$G$500,Estimate!$A$5:$A$500,A5) and C5 actual from Site expenses (SUMIFS).
3. E5 used % and F5: =IF(C5>B5,"Over budget",IF(C5>0.9*B5,"Near limit","OK")) (budget vs actual).
4. Rows 12 to 17: work estimate, contingency, design fee on work + contingency, taxable, GST and grand total.

Step 4. Payments and Quotation

1. Payments: milestones Booking 10%, Material order 40%, Installation 40%, Handover 10%. C5 =ROUND(Summary!$B$17*B5,0).
2. F5 status =IF(E5<>"","Received",IF(D5<Setup!$B$3,"Overdue","Upcoming")).
3. Quotation lists room totals and the final amount. Set the print area.

Step 5. Dashboard

1. KPI cards: grand total, work estimate, spent so far, budget used, received from the client and rooms over budget.
2. Charts: estimate and actual by room, and estimate by item.

3. Formulas used

Every formula above is written in the template, so you can click a cell and see it in the formula bar. All values on this page were recalculated in LibreOffice with zero errors.

4. Common mistakes

1. One lump sum per room. Line items show the client what they pay for and show you where costs run over.
2. Design fee on GST. Work out the fee on work + contingency, then GST on the taxable total.
3. Site bills without a room. An expense not booked to a room never reaches budget vs actual.
4. Milestones that do not add to 100%. Check the Total row on Payments shows 100%.
5. Using old rates. Update the rate card when plywood or labour rates change, before the next quote.

5. More real examples

Example 1: Office fit-out. Rooms become zones (reception, cabins, pantry) and add workstations as an item.

Example 2: Kitchen-only studio. One room with cabinets, countertop, hardware and appliances as items.

Example 3: Renovation contractor. Add demolition and civil items, and track site progress like the construction site system.

Quick revision cards

Englishमराठीहिंदी

Quick revision

Each card shows formulas from this page, each with an example and its answer from the template. Scan the QR code on a card to open this lesson. All names and numbers are made up for practice.

More cards: Ravi Sir's Cards.

6. Frequently asked questions

How do I make an interior estimate in Excel?

A rate card and one line per item per room: qty × material rate and qty × labour rate, looked up with XLOOKUP.

How do I compare estimate and actual by room?

SUMIFS the estimate lines and the site expenses by room, then actual ÷ estimate.

How do I add design fee and GST?

Fee on work + contingency, then GST on work + contingency + fee, as in Summary rows 12 to 17.

What GST applies to interior work?

It depends on whether it is a works contract or supply plus service. Keep the rate as an input and confirm with your accountant.

How do I make a payment schedule?

Grand total × milestone % per row, with due date, received date and a status.

7. Quick quiz

Ten questions on this page. Sign in to save your score.