Home Improvement Budget Calculator
Work out whether your home improvement budget covers the job — your budget against your estimate, with the remainder and the percent used.
A budget is only useful if you can see it next to the estimate. This calculator puts them side by side: your budget, your estimate with contingency, what is left, and how much of the budget is used.
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
- Enter your total budget.
- Enter your cost for each category.
- Set a contingency.
- Read the estimated total, the remaining amount and the percent used.
Worked example
| Budget | $50,000 |
|---|---|
| Estimate | Kitchen $15,000 + Bathroom $8,000 + Flooring $5,000 + Other $2,000 = $30,000 |
| Contingency (10%) | $3,000 |
| Estimated total | $33,000 |
| Remaining | $50,000 − $33,000 = $17,000 |
| Budget used | $33,000 ÷ $50,000 = 66% |
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 do I set a renovation budget?
Start with what you can afford, then estimate the work and compare — that is what this calculator does. If the estimate is over the budget, cut scope (cheaper finishes, fewer rooms) rather than cutting the contingency.
What if my estimate is over my budget?
The remaining amount will be negative. Cut scope first: cheaper materials, fewer rooms, or phase the work. Do not cut the contingency — that is what pays for surprises.
How much contingency should I keep in the budget?
10–20% of the estimate. The contingency is part of the budget, not extra — this calculator adds it into the estimated total before comparing with the budget.
Is this a quote?
No. It is a comparison of your own budget and your own estimate — not a guaranteed quote. Get written contractor 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.