How to use this calculator
- Choose cosmetic refresh or full renovation for the scenario label.
- Enter your measured bathroom area and your own costs for each line item.
- Save one scope scenario, change the amounts, and compare it to a second.
The calculation formula
Base subtotal = sum of eight cost categories. Total = base subtotal + subtotal × contingency% + subtotal × tax allowance%.
Worked example
If category allowances add to $11,650 and contingency is 15%, the total without additional tax is $13,397.50.
Assumptions and limitations
- Scope selection does not imply a secretly applied price multiplier.
- Waterproofing design and electrical/plumbing work require appropriate qualified professionals.
Actual project costs may be affected by supplier rates, material grade, labor market, location, disposal, site condition, access, permits, taxes, and schedule. All entered prices are yours to revise. See our methodology and disclaimer.
Frequently asked questions
Does full renovation automatically add costs?
No. Adjust the category allowances to match full-scope work and compare snapshots.
Are waterproofing materials included?
There is a dedicated editable allowance; suitability and installation must be professionally assessed.