Estimator inputs
Use the factors to match your site, market, and finish level.
Formula used
This estimator builds a direct base cost from area and a rate, then adjusts it with market and scope factors:
After that, adders are applied in a stacked way:
contingency = (directBase + overhead) × contingency%
profit = (directBase + overhead + contingency) × profit%
tax = (directBase + overhead + contingency + profit) × tax%
grandTotal = subtotal + tax + fixedAddOns + lineItems
Material/Labor/Equipment shares are normalized to 100% for reporting only; they do not change the grand total.
How to use this calculator
- Enter the project area and choose your unit.
- Set a realistic base rate per ft² from local benchmarks.
- Adjust location, complexity, and quality to match the scope.
- Add timeline and escalation rate for longer schedules.
- Apply overhead, contingency, profit, and tax percentages.
- Include fixed fees and optional custom line items.
- Press Calculate estimate to view totals and downloads.
Example data table
These sample figures show how factors and adders affect totals.
| Scenario | Area | Base rate | Factors (L×C×Q) | Adders (OH/Cont/Profit/Tax) | Illustrative total |
|---|---|---|---|---|---|
| Standard build | 1,500 ft² | $120/ft² | 1.00 × 1.00 × 1.00 | 8% / 10% / 12% / 5% | $278,784.00 |
| Premium finish | 1,500 ft² | $120/ft² | 1.05 × 1.10 × 1.15 | 9% / 12% / 12% / 5% | $394,845.36 |
| Higher market | 1,500 ft² | $120/ft² | 1.25 × 1.00 × 1.00 | 10% / 12% / 14% / 5% | $408,240.00 |
Example totals are illustrative only and exclude custom line items unless entered.
Scope drivers that shape the base rate
A base rate works best when it matches scope. Use higher rates for multi‑storey structures, basements, complex façades, premium MEP systems, or tight access. Typical planning inputs include storey count, structural system, façade type, and service intensity. When you increase complexity or quality factors, the calculator scales direct cost before adders, reflecting how real budgets expand across trades. Document assumptions beside the rate so later revisions remain comparable across teams.
Area, units, and rate normalization
The calculator converts ft² and m² consistently, so your rate stays meaningful. If you collect market benchmarks in one unit, keep your base rate in that same unit and switch the area unit as needed. For mixed‑use projects, consider a weighted average rate or run separate estimates per use, then sum. This reduces distortion from very different fit‑out allowances. For renovation, measure gross area but adjust rates for demolition and phasing carefully.
Market, location, and time escalation
Location and market factors represent labour availability, logistics, and competitive pressure. Time escalation applies a compounding uplift to capture inflation across the schedule. For short durations, escalation may be near zero; for longer programs, even a modest annual rate materially changes totals. Use realistic timelines and update escalation when procurement dates shift.
Overhead, contingency, profit, and taxes
Adders are applied after scaled direct cost. Overhead covers supervision, temporary works, safety, and site utilities. Contingency addresses uncertainty: keep it higher for concept designs and reduce it as drawings, quantities, and vendor quotes improve. Profit and tax vary by contract type and jurisdiction, so treat them as configurable rather than fixed.
Line items, fees, and audit-ready breakdowns
Fixed fees, permits, and professional services are captured as lump sums, while optional line items let you add known scope gaps such as utility connections or specialist testing. Because each component is shown separately, you can explain “what changed” between revisions, export a CSV for review, and generate a PDF snapshot for approvals and record keeping.
FAQs
What is the difference between base rate and total rate?
The base rate represents direct build cost per area before adjustments. The total rate includes market factors, escalation, overhead, contingency, profit, taxes, fixed fees, and any custom line items.
How do I choose a realistic base rate?
Start with recent comparable projects in your area. Cross‑check with published cost guides and supplier quotes. Use a mid value for early design, then tighten the rate as quantities and specifications become clearer.
When should I increase contingency?
Increase it when drawings are incomplete, scope is evolving, or procurement risks are high. Concept estimates often carry higher contingency, while detailed BOQs and firm quotes support lower contingency.
How does escalation work in the calculator?
Escalation compounds the adjusted direct cost over the project duration using an annual rate. Longer timelines amplify the effect, so update duration and rate whenever start dates, procurement windows, or delivery phases change.
Can I estimate mixed-use projects with one run?
Yes, but accuracy improves if you run separate estimates for each major use, such as residential, retail, and parking, then combine totals. Different uses can have very different base rates and factor settings.
Are exports suitable for client proposals?
Exports provide a clear snapshot and are useful for reviews and approvals. For proposals, add your scope notes, exclusions, and assumptions alongside the exported breakdown so readers understand what the estimate includes.