Interior Fit-Out Cost Calculator

Plan interiors confidently with quick, editable cost inputs. See totals, trade splits, and risk buffers. Download a report, share estimates, then refine scope easily.

Calculator Inputs
Choose a preset or enter custom rates. Adjust factors and allowances to match your project.
Results appear above after you submit.
Used in reports and exports.
Use measurable fit-out area, not gross area.
Submit once after changing to refresh defaults.
Totals and exports use this currency.
Multiply base rates by this factor.
Adjust for city, access, and logistics.
Higher for night work or tight coordination.
Covers cutting, breakage, and small losses.
Contractor OH&P on adjusted trades.
Architect + engineering + PM allowance.
Risk buffer for unknowns and changes.
Enter applicable sales/VAT percentage.
Use for long procurement or inflation risk.
Scope selection
Tick the items included in your fit-out package.
When to use custom rates
Choose custom when you already have trade quotes or unusual requirements.
Trade rates (per m²)
Rates are editable with custom or override mode.
Trade Rate
Demolition & protection
Partitions & doors
Flooring
Ceiling
Painting
MEP services
Lighting & controls
Joinery & millwork
IT & low voltage
Loose furniture
Preliminaries
Rates are multiplied by area, then adjusted with factors and allowances.
Reset
Formula used

The calculator builds a trade sub-total, then applies project factors and allowances.

Trade Sub-total = Area × Σ(Trade Rate per m²)
Factored Cost = Trade Sub-total × Location Factor × Complexity Factor
Pre‑tax Total = Factored Cost + Wastage + OH&P + Design/PM + Contingency + Escalation
Grand Total = Pre‑tax Total + Tax
Cost per m² = Grand Total ÷ Area

Use higher factors for restricted access, night shifts, or heavy coordination.

How to use this calculator
  1. Enter the net area you will fit out.
  2. Select a quality preset or choose custom rates.
  3. Tick the scope items included in your package.
  4. Adjust factors for location and complexity.
  5. Set allowances for risk, fees, and tax.
  6. Press Calculate to view the breakdown above.
  7. Use CSV or PDF export for sharing and filing.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.

Interior fit-out cost planning notes

1) Key cost drivers in most fit-outs

Fit-out budgets are commonly led by MEP services, joinery, partitions, and finishes. If scope adds HVAC redistribution, extra power, or fire alarm modifications, services can quickly become the largest share. Confirm who supplies furniture and IT, because moving these packages between parties can distort comparisons.

2) Why area-based trade rates work early

Early designs change fast and quantity take-offs are unreliable. A rate per m² approach provides a consistent baseline that you can refine later. This calculator multiplies each selected trade rate by net fit-out area to form a trade sub-total, then applies factors and allowances. Use custom rates once you have quotes and approved specifications.

3) Factors and allowances you should document

Location and complexity factors align estimates to site reality. Planning ranges are often 0.9–1.2 for normal access and 1.2–1.6 for constrained logistics, occupied works, or phased handovers. Allowances for wastage, OH&P, design/PM, contingency, escalation, and tax should stay visible, because they explain the difference between a raw sum and the final budget.

4) Reading cost per m² for benchmarking

Cost per m² supports option studies across different floor plates. Track it by quality level and by scope boundary (base build versus tenant works). If it spikes, check which trades are included and whether factors or contingency were raised. Use the trade breakdown to identify the best value-engineering targets.

5) A practical workflow for better accuracy

Start with a preset, confirm the scope checkboxes, then set factors to match logistics. Select contingency by maturity: 15–20% concept, 10–15% schematic, and 5–10% when coordination is advanced. Apply escalation when procurement lead times are long or prices are volatile. Replace presets with trade quotes as they arrive, compare at least two suppliers per trade, and export the report to record assumptions before each revision.

FAQs

1) What area should I enter?

Enter the net internal area being fitted out. Exclude plant rooms and landlord-only zones unless you are paying for their interior works. Consistency matters more than the specific standard you use.

2) When should I use custom rates?

Use custom rates when you have supplier quotations, a detailed bill of quantities, or unusual finishes. Custom inputs reduce reliance on assumptions and improve the trade-by-trade credibility of the total.

3) What do location and complexity factors represent?

They adjust costs for logistics, access restrictions, working hours, and coordination effort. Higher values suit tight sites, phased handovers, occupied buildings, or premium HSE requirements.

4) How do I select a contingency percentage?

Base it on design maturity and risk. Early concept often needs 15–20%, while coordinated designs may use 5–10%. Increase it if scope is uncertain or approvals could trigger changes.

5) Should I include furniture and IT?

Include them only if they are in your procurement scope. Many projects split these packages. If excluded, ensure the benchmark you compare against is also excluding them.

6) Why does the grand total differ from the trade subtotal?

The grand total includes factors plus allowances such as wastage, OH&P, design/PM, contingency, escalation, and tax. These items can materially change budgets and should be stated explicitly.

7) Can I use the exports for approvals?

Yes, as a planning-grade summary. Attach notes on scope boundaries, rates, and factors. For contract approvals, replace assumptions with quotes, specifications, and measured quantities.