How to estimate a renovation budget
Renovation cost depends on the area, the rooms involved and the level of finish. Kitchens and bathrooms cost the most per square foot.
The formula
Budget = square feet × cost per square foot × (1 + contingency %)
Worked example
Renovating 500 square feet at $100 per square foot with a 15% contingency comes to $57,500.
How to use this calculator
Enter the square footage you plan to renovate, a low and a high cost per square foot, and a contingency percentage. The renovation cost calculator multiplies them to give a budget range, the midpoint and the contingency included. Add your home’s value to see the midpoint as a share of that value. Enter only the area being worked on, not the size of the whole house, unless every room is included.
What the result means
The result is a planning range, not a quote. As a rough guide, renovations run from about $15 to $150 per square foot depending on scope. Cosmetic work such as paint and flooring sits at the low end. Projects that replace kitchens and bathrooms or change the layout sit at the high end.
The low figure shows what the job might cost if the scope stays modest. The high figure shows where it could go with better finishes or more work. Plan around a number you could afford at the upper end, and use contractor quotes to narrow the range.
More examples
The same 500 square feet at different scopes
Each row includes a 15% contingency.
| Cost per square foot | Before contingency | Budget with 15% |
|---|---|---|
| $15 | $7,500 | $8,625 |
| $50 | $25,000 | $28,750 |
| $100 | $50,000 | $57,500 |
| $150 | $75,000 | $86,250 |
How the contingency moves the budget
On the $50,000 job from the worked example, a 10% contingency gives $55,000, 15% gives $57,500 and 20% gives $60,000.
Pricing rooms separately
One rate for the whole project hides the expensive rooms. Suppose a project covers a 150 square foot kitchen at $150 per square foot and 350 square feet of bedrooms at $30 per square foot. The kitchen is $22,500 and the bedrooms are $10,500, for $33,000 in total. With a 15% contingency the budget is $37,950. The kitchen is under a third of the area and more than two thirds of the cost.
What changes the result
- Scope. Refreshing surfaces costs far less per square foot than replacing cabinets, fixtures and wiring.
- Which rooms. Kitchens and bathrooms pack plumbing, cabinets, tile and appliances into a small space.
- Finish level. Materials come in a wide range of prices for the same square footage.
- Layout changes. Moving walls or plumbing adds labor and often a permit.
- Age of the home. Older homes are more likely to need extra work once walls are opened, which is why they call for a larger contingency.
Common mistakes
- Applying one cost per square foot to rooms with very different scopes.
- Setting the contingency to zero to make the number fit.
- Entering the whole house when only part of it is being renovated.
- Leaving out permits, design fees, and the cost of living elsewhere or eating out while the work is done.
- Treating the estimate as a price. Only a written quote for your home reflects local labor and the materials you choose.
Related calculators
Break the budget down by trade with the flooring calculator and the paint calculator. If the work is close to a rebuild, compare it with the cost to build a house calculator. If you plan to borrow against your home to pay for it, the HELOC calculator estimates how much you could draw. Newly Property is not a lender or a contractor, so ask your lender what you qualify for before you commit to a scope.
Frequently asked questions
How much contingency should I add?
10% to 20%, and more for older homes.
What usually pushes costs over budget?
Hidden problems behind walls, changes made mid-project, and moving plumbing or walls.
Do I need a permit?
Usually for structural, electrical and plumbing work. Check with your local building department.
How much does it cost to renovate 1,000 square feet?
At roughly $15 to $150 per square foot, between $15,000 and $150,000 before contingency. Where your project falls depends on the scope and the rooms involved.
Why do kitchens and bathrooms cost more per square foot?
They combine plumbing, electrical work, cabinets, counters, tile and fixtures in a small area, so more trades and materials go into each square foot.
Is the contingency likely to be spent?
Plan as if it will be. It exists for hidden problems and mid-project changes, and any part you do not use stays in your pocket.
How do I get a firmer number?
Write down the scope room by room and ask more than one contractor for a written quote on the same list, so the prices can be compared.