Renovation budget calculator
A sensible spending range for your renovation, based on your home's value — with a check for over-improving, then a look at what you recoup at resale.
How much should you spend on a renovation?
A common rule of thumb is to keep a whole-home renovation in the region of 5–15% of your home's value: around 5% for a light refresh, ~10% for a typical update, and up to 15% for an ambitious one. Per-room, kitchens can justify up to about 15% of home value and bathrooms roughly 5–10%. These aren't hard limits — they're a guard rail that keeps your spend in proportion to what the home, and your local market, can support.
Whole-home budget by home value
| Home value | Light (5%) | Typical (10%) | Ambitious (15%) |
|---|---|---|---|
| $300,000 | $15,000 | $30,000 | $45,000 |
| $450,000 | $22,500 | $45,000 | $67,500 |
| $600,000 | $30,000 | $60,000 | $90,000 |
| $800,000 | $40,000 | $80,000 | $120,000 |
Per-room guidance
| Room / project | Share of home value | Notes |
|---|---|---|
| Kitchen | 10–15% | The room buyers scrutinise most; easy to over-spend. |
| Bathroom | 5–10% | Cost concentrates in plumbing, tile and fixtures. |
| Whole-home refresh | 5–10% | Paint, flooring, lighting — high impact per dollar. |
| Major addition | 10–20%+ | Adds space but watch the local price ceiling. |
The over-improvement trap
The bigger risk is over-improving: once a project pushes past ~20% of your home's value, you're increasingly likely to spend more than your local market will pay back. A $150,000 kitchen in a $400,000 neighbourhood simply can't be appraised back, because appraisers and buyers price your home against comparable sales nearby. Before committing to an ambitious budget, check what renovated homes actually sell for on your street — the ceiling is set by the neighbourhood, not the showroom.
A worked example
On a $450,000 home, a typical update budget is about $45,000 (10%), with roughly $6,750 of that held back as a 15% contingency. A kitchen within that could run to ~$67,500 (15%) at the top end — but spending $110,000 (24%) would very likely over-improve for the market. The percentage keeps the ambition in check; the ROI calculator then tells you how much of the spend comes back.
Budget is only half the question
The other half is how much you recoup. See which projects pay back best in the ROI calculator and the best-value projects guide, or read how to avoid overcapitalising. If you'll be borrowing, size the repayments with the renovation loan calculator.
Frequently asked questions
How much should I spend on a renovation?
A common guideline is 5–15% of your home's value for a whole-home renovation: around 5% for a light refresh, ~10% for a typical update, and up to 15% for an ambitious one. Per room, kitchens can justify up to about 15% of home value and bathrooms roughly 5–10%.
What is over-improving, and why does it matter?
Over-improving is spending more than your local market will pay back. Once a project pushes past ~20% of your home's value, the extra spend increasingly won't appear in the appraisal or sale price. A $150,000 kitchen in a $400,000 neighbourhood can't be supported by nearby comparable sales.
Should I budget by home value or by the actual project scope?
Use home value for a first-pass sanity check, then price the real scope line by line. The percentage rules stop you over-committing; the detailed quote tells you what the work actually costs. Our project cost guides show what's typically included for each project.
How much contingency should I include?
Keep 10–15% of the budget aside for surprises — hidden water damage, old wiring, non-standard sizing, or scope creep. Older homes and structural projects sit at the higher end. A contingency you don't use becomes a nice buffer; one you didn't plan for stalls the job.
Does a bigger budget mean a better return?
Not usually. The highest-ROI projects tend to be mid-budget curb-appeal and refresh work, not the most expensive gut renovations. See which projects pay back best in the ROI calculator before deciding where the money goes.
These are general planning ranges, not a recommendation for your specific home or finances. Confirm with a local agent and contractor quotes. Not financial advice. Reviewed July 2026.
Know the return, too
A budget is only half the picture — see how much of the spend comes back when you sell.
Open the ROI calculator →