Room Renovation Cost Calculator
Get a trade-by-trade planning estimate for renovating a single room. Adjusts for renovation scope, local market cost level and room size.
Renovating multiple rooms? Try the full Home Renovation Cost Estimator →
Quick Start
Tip: This is a broad planning estimate. Always get at least two contractor quotes before committing to a budget.
Project
Room Details
Scope & Market
Market cost level adjusts the estimate for local labour and supply cost differences — roughly ±35% from the average baseline. Currency selection converts the output using approximate exchange rates. Both adjustments are planning tools, not financial data.
Trades
Select the trades involved in this room. Only selected trades are included in the estimate.
How room renovation costs are calculated
How the estimate works
This calculator applies typical cost ranges per m² for each selected trade at the chosen scope level, then adjusts for your market cost level. Cosmetic, mid-range and full renovation scopes roughly double the cost per m² at each step, reflecting the additional trades and preparation required.
Market cost level
The market cost level adjusts the baseline estimate by approximately 35 percent in either direction. Low markets (rural areas, Eastern Europe) sit around 65 percent of the average baseline. High-cost markets (London, Scandinavia, Switzerland, major Australian cities) sit around 155 percent. This is a planning adjustment, not a currency conversion.
Contingency logic
A common rule of thumb is to hold 10–20 percent contingency. The calculator suggests 20 percent for full renovations, electrical work, or projects involving four or more trades — and 10 percent for lighter scopes. These are planning starting points; some sources recommend 10–15 percent even for larger projects. Use the figure as a prompt to set money aside, not as a fixed standard. Contingency covers unplanned discoveries, scope changes and price movement between estimate and execution.
What this estimate does not include
Bathroom and kitchen renovations involve specialist plumbing and fitting costs not covered here — these room types are best estimated with a dedicated calculator. Structural work (removing walls, new openings) and external work are also outside this calculator's scope.