Room Renovation Calculator
Work out what renovating one room will cost — from the room size and your line items, with contingency, tax and cost per square foot.
One room is the smallest renovation — and the easiest to price badly, because the small costs add up. This calculator keeps every line visible and gives you the cost per square foot.
All prices are entered by you. This site publishes no construction prices, and results are estimates, not guaranteed quotes.
Your results
Enter your measurements and press Calculate.
Quantities are rounded up to whole tiles, planks, boxes or bags, after the wastage allowance. Cost appears only when you enter a price.
Formula
All lengths are converted to a single unit before the calculation: 1 ft = 0.3048 m, 1 in = 25.4 mm, 1 ft² = 0.09290304 m², 1 yd² = 9 ft². Material quantities are rounded up — you cannot buy part of a tile, plank or bag.
How to use this calculator
- Measure the room length and width.
- Enter your cost for each line item.
- Set a contingency and your local tax rate.
- Read the total and the cost per square foot.
Worked example
| Room | 12 ft × 15 ft = 180 ft² |
|---|---|
| Line items | Flooring $2,000 + Painting $800 + Fixtures $1,500 + Labour $3,000 + Other $500 = $7,800 |
| Contingency (10%) | $780 |
| Tax (8%) | ($7,800 + $780) × 0.08 = $686.40 |
| Total | $9,266.40 |
| Cost per ft² | $9,266.40 ÷ 180 = $51.48 per ft² |
Check it by hand: every step above uses the formula in the box. If your numbers match the example inputs but the calculator gives a different answer, please report it via the contact page.
Frequently asked questions
How much does it cost to renovate a room?
It depends on the room and the finish. Enter your line items above and the calculator gives your total and your cost per square foot — from your numbers, not a guessed average.
What should I include in a room renovation?
Flooring, painting, fixtures (lights, fittings), labour, and anything else (built-ins, windows, doors). The categories above cover the usual ones — put the rest in 'Other'.
How much contingency for one room?
10% for a straightforward room, 20% if the room is old or the work opens walls. One room's surprises are smaller than a whole house's, but they still happen.
Are these figures a quote?
No. They are estimates built from your own numbers — not guaranteed quotes. Get written quotes for the real price.
Related calculators
Estimates only. Results are for planning. Measure twice, confirm box coverage and tile sizes on the packaging you buy, and follow the manufacturer's instructions. See the disclaimer.