Renovation Cost Calculator
Scope & costs
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Know what this estimate is based on
- Jurisdiction
- United States — state and local practice
- Scope and limitations
- Educational estimate only. U.S. real estate costs are local: property tax rates, transfer and recording taxes, title practice, who customarily pays which closing cost, and landlord-tenant rules all change by state and often by county or city. Agent commission is negotiable and, since the 2024 NAR settlement, buyer-agent compensation is negotiated separately rather than assumed. Only a lender's Loan Estimate, a title company's fee sheet or a signed contract binds a number.
- Source links checked
- Jul 30, 2026
Built and regression-tested by Smart Tools Lab. It has not been individually reviewed by a licensed financial, tax, or legal professional.
How to use
- 01
Enter the project's square footage and the hard cost per square foot from your contractor's bid.
- 02
Enter fixtures and appliances separately — they are usually an allowance in the bid rather than a firm price.
- 03
Enter permits and design fees.
- 04
Open Advanced options for the general contractor's overhead and profit and the contingency.
- 05
Read the all-in budget and the true delivered cost per square foot. That second figure is what the job actually costs, not what the bid says.
Formula
The hard cost is the project square footage times the cost per square foot — the bid. The general contractor's overhead and profit is a percentage of that hard cost, because that is what a contractor marks up. The subtotal adds fixtures, permits and anything else, and the contingency is a percentage of that whole subtotal rather than of the hard cost alone, since a surprise can arrive in any line. The all-in budget is the subtotal plus the contingency, and the true delivered cost per square foot is that budget divided by the project area — rendered as a dash when no area is entered. Both percentages keep their defaults, because a zero contingency and a zero overhead are claims about the job rather than empty fields.
Example
A 200-square-foot kitchen at $250 a square foot of hard cost, with $12,000 of fixtures and appliances, $3,500 of permits and design, $2,000 of other costs, 20% overhead and profit and a 15% contingency. Hard cost: 200 x $250 = $50,000. This is the number on the bid. Overhead and profit: $50,000 x 20% = $10,000. Subtotal: $50,000 + $10,000 + $12,000 + $3,500 + $2,000 = $77,500. Contingency: $77,500 x 15% = $11,625. All-in: $89,125 — or $446 a square foot delivered. The bid said $50,000 and the job costs $89,125. That $39,125 gap is not overcharging; it is the four things a bid does not include, and every one of them is real. Fixtures get chosen, permits get pulled, the contractor gets paid to run the job, and something is found behind the wall. The delivered figure of $446 a square foot against a $250 bid is the number to carry into the next quote. When a contractor says $250 a foot and another says $310, the second may be quoting more of the job — and comparing the two on the headline is how people pick the more expensive one.
Definitions
- Hard cost
- The labour and materials for the work itself. The number on the contractor's bid.
- Overhead and profit
- The general contractor's margin, commonly 15% to 25%. Pays for supervision, insurance and licensing.
- Contingency
- A reserve for what is found once work starts. Ten to twenty percent depending on the age of the building.
- Allowance
- A placeholder budget for fixtures or finishes not yet chosen. Where budgets most often break.
- Change order
- A documented change to the agreed scope, priced separately and usually at a premium.
- Draw schedule
- The agreed sequence of payments tied to completed milestones.
- Retainage
- A percentage held back until the punch list is complete, commonly 5% to 10%.
- Punch list
- The final list of defects and unfinished details before the job is accepted.
- Delivered cost per square foot
- The all-in budget divided by project area. What the work actually costs, not what the bid says.
- Permit
- Municipal approval required for structural, electrical and plumbing work. Unpermitted work causes trouble at resale.
- Scope of work
- The written description of what is included. The only fair basis for comparing bids.
- Subcontractor
- A specialist trade hired by the general contractor. Their scheduling is what the overhead pays for.
Good to know
A bid is a hard cost, not a budget
The single most common renovation experience in the US is a finished job costing a third more than the quote, and the arithmetic explains why. A $50,000 bid covers labour and materials for the described scope. On top of it sit the general contractor's overhead and profit, the fixtures and appliances that were an allowance rather than a price, the permits and design fees, and a contingency for what is found once walls open. Here that is $89,125 all in — $446 a square foot delivered against the $250 the bid implied. None of the additions is padding and all of them arrive. The useful discipline is to build the budget from the delivered figure and carry that number into the next quote, because comparing a $250 bid against a $310 bid on the headline is how people choose the more expensive contractor.
What 20% of overhead and profit actually buys
Fifteen to twenty-five percent is the standard general contractor margin in US residential work, and it pays for real things: scheduling and sequencing the trades, supervision, general liability and workers' compensation insurance, licensing and bonding, permit management, warranty on the work, and the cost of the jobs that were bid and never won. A bid without it usually means you are the general contractor — which is a legitimate choice that saves $10,000 here and costs you the subcontractor relationships, the scheduling, the permit process and the liability when a trade damages something. The other thing the margin buys is recourse. An uninsured, unlicensed crew that disappears mid-job leaves the homeowner with a partially demolished kitchen and no remedy, and that scenario is common enough that most states run a licensing board specifically about it.
The contingency is a budget line, not optimism
Ten to fifteen percent on a straightforward project, twenty percent or more on anything built before about 1980 or where walls are coming down. The reserve is not padding — it is the budget for a specific and predictable class of discovery: knob-and-tube wiring that a permit now requires replacing, galvanized supply lines, rot under a shower pan, asbestos in floor tile or duct wrap, undersized framing a previous owner cut through, and code upgrades that get triggered the moment an inspector is involved. Any one of them consumes a large share of a 15% reserve on its own. Projects that skip the contingency do not come in on budget; they stall halfway, which is more expensive than the contingency would have been because a paused job still pays for scaffolding, storage and a kitchen you cannot use.
Allowances are where budgets quietly break
An allowance is a placeholder the contractor budgets for something you have not chosen — tile, fixtures, appliances, lighting, countertops. They are set conservatively so the bid looks competitive, and they are almost always below what people actually select. A $4,000 appliance allowance against the range you want at $7,500 is a $3,500 overrun that arrives as a change order rather than as a surprise, which makes it feel like your fault rather than a structural feature of how bids are written. The fix is straightforward and unpopular: price your actual selections before signing, and put real numbers in place of the allowances. It makes the bid look more expensive and makes the project cost the same, which is the correct trade. It also removes the most common cause of mid-project change orders, which are priced at a premium because the schedule is already set.
Paying for it: draws, retainage and the lien risk
A normal payment structure is a modest deposit, then draws tied to completed milestones, with 5% to 10% held back until the punch list is finished. A contractor who wants most of the money up front is telling you something about their cash flow, and paying far ahead of the work is the single most reliable way to lose money on a renovation. Two protections are worth knowing. Mechanic's lien laws in every state let unpaid subcontractors and suppliers place a lien on your home even if you paid the general contractor in full — so collect lien waivers with each draw. And most states require a written contract above a threshold amount with specified terms, several give a short right of rescission, and the state licensing board is a real avenue when things go wrong. Check the licence and the insurance certificate before the first payment, not after.
Frequently asked questions
Why is the all-in budget so much higher than the bid?
Because a bid is the hard cost of the work. Overhead and profit, fixtures, permits, design and a contingency are all real and all arrive anyway. On these figures the $50,000 bid becomes an $89,125 budget — and the finished job costing a third more than quoted is the single most common renovation experience.
Is 20% overhead and profit normal?
Yes. Fifteen to twenty-five percent is the standard range for a general contractor, and it pays for scheduling, supervision, insurance, licensing and warranty. A bid without it usually means you are the general contractor, which is a real job with real liability.
How much contingency do I need?
Ten to fifteen percent on a straightforward job, twenty percent or more on anything older than about 1980 or where walls are coming down. It is not padding — it is the budget for what is found behind the plaster, and jobs that skip it stall.
What actually shows up in the contingency?
Knob-and-tube wiring, galvanized plumbing, rot under a shower pan, asbestos in floor tile or duct tape, structural work a wall was hiding, and code upgrades a permit triggers. Any one of them absorbs a large share of a 15% reserve on its own.
What are typical costs per square foot?
Enormously variable by region and finish. Mid-range kitchen and bathroom work commonly runs $150 to $350 a square foot of project area, and high-end well beyond it. Whole-house work is usually quoted lower per foot because much of the area is simpler.
Should fixtures be inside the bid?
Usually they are an allowance — a placeholder the contractor budgets against. Allowances are where budgets quietly break, because the allowance is set low and the tile you choose is not. Price your actual selections and enter them here rather than trusting the placeholder.
Do I need a permit?
For structural work, electrical, plumbing and most additions, yes. Unpermitted work causes trouble twice: at inspection when you sell, and with an insurer after a claim. Permit and design fees commonly run 1% to 5% of project cost.
How do I compare contractor bids?
On scope, not on price. A bid $20,000 lower usually excludes something — the electrical, the disposal, the finish carpentry, or a realistic fixture allowance. Ask each contractor to price the identical written scope, and the spread narrows dramatically.
Should I act as my own general contractor?
It saves the overhead and profit — $10,000 on this job — and costs you the scheduling, the subcontractor relationships, the permit management and the liability. It is a reasonable trade for a confident owner with time, and a poor one otherwise.
When are draws paid?
Typically a deposit, then payments at milestones, with a retainage of 5% to 10% held until the punch list is finished. Never pay far ahead of the work — a contractor who wants most of the money up front is a contractor with a cash-flow problem.
How much does a change order cost?
More than the same work would have cost in the original scope, because the schedule and the ordering are already set. Deciding the scope fully before work starts is the cheapest cost control available.
Will I get this money back at sale?
Partly, and usually less than the cost. The Renovation ROI Calculator prices it, including the interest if you borrow and the selling costs — both of which cost-versus-value tables leave out.