Bathroom Renovation Cost Calculator
Get a trade-by-trade planning estimate for your bathroom renovation. Adjusts for renovation scope, local market cost level and bathroom size.
Renovating multiple rooms? Try the full Home Renovation Cost Estimator →
Quick Start
Tip: A 20% contingency is built in — bathroom renovations have a higher risk of hidden issues. Always get at least two or three quotes before committing.
Project
Bathroom Details
Bathroom type is for reference only and does not affect the calculation. The size input drives the estimate.
Scope & Market
Market cost level adjusts for local labour and supply differences — roughly ±35% from the average baseline. Currency selection converts the output using approximate exchange rates.
Trades
Select the trades involved. Only selected trades are included in the estimate — even if the renovation scope description mentions additional work. Tiling rates are per floor area including a typical wall tiling allowance. Plumbing, tiling, electrical and waterproofing use a minimum of 4 m² to account for fixed costs that don't scale with very small bathrooms.
Optional add-ons
How bathroom 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 local market cost level and converts to your selected currency using approximate exchange rates.
Minimum effective area
Plumbing, tiling, electrical and waterproofing include significant fixed costs that do not scale with bathroom size. A plumber fitting a new toilet, basin and shower enclosure charges broadly similar labour whether the bathroom is 3 m² or 6 m². To reflect this, the calculator uses a minimum effective area of 4 m² for these four trades, regardless of the size you enter. This prevents unrealistically low estimates for very small bathrooms.
Tiling rates
Tiling costs are calculated per floor area, but the rates include a typical allowance for wall tiling. Bathrooms require tiling on both floors and walls — often to full height in a shower or wet area. The per-floor-area rate captures this combined scope rather than requiring separate inputs for floor and wall area, which most users do not know in advance.
Contingency
A 20 percent contingency is applied to all bathroom renovations. This reflects the elevated risk of hidden issues: water damage behind tiles, outdated plumbing, failing waterproofing, or substandard previous work that is only discovered during strip-out. A common rule of thumb is 10 to 20 percent for renovations generally. For bathrooms, 20 percent is the more appropriate starting point.
What this estimate does not include
Kitchen renovations, structural work and room extensions are outside the scope of this calculator. For a full multi-room project, the Home Renovation Cost Estimator covers the complete budget across rooms and trades.