About the Home Renovation Budget Calculator
This home renovation budget calculator turns a list of project costs into a realistic all-in budget. Enter what you expect to spend on demolition, materials, labor, fixtures and appliances, other work, permits and design fees, then add the general contractor’s markup, sales tax on purchased goods and a contingency reserve. It shows the total, the cost per square foot and whether you are over or under the amount you have set aside.
It is useful when planning a kitchen or bathroom remodel, a basement finish or an addition, when comparing contractor bids line by line, or when deciding how much to borrow with a home equity loan or HELOC. Setting markup to zero models a DIY or owner-managed project.
Markup is applied to the construction work (demolition, materials, labor, fixtures and other work) but not to permits and design fees, which are usually passed through at cost. Sales tax is applied to materials and fixtures only. Contingency is applied last, to everything, because surprises — rot behind a wall, outdated wiring, change orders — usually cost more than expected; 10–20% is a common reserve, more for older homes.
With the default inputs, the total renovation budget is $62,744.00. Change any value above to recalculate instantly.
How to use the home renovation budget calculator
- 1Enter your estimate or bid for each line item — leave unused items at 0.
- 2Set the contractor markup (0 if you are managing the job or bids already include it).
- 3Enter your local sales tax rate and a contingency reserve (10–20% is typical).
- 4Add the project area and the money you have available.
- 5Review the total, cost per square foot and budget check, then adjust the scope.
Formula and method
The calculator adds every line item to get the direct cost. A general contractor’s markup — the percentage added for overhead, supervision and profit — is applied to the construction work they manage, but not to permits and design fees, which are usually billed at cost. Sales tax is applied only to purchased goods (materials, fixtures and appliances), since labor is untaxed in most US states.
The contingency percentage is applied last, to the subtotal including markup and tax, so the reserve can cover any part of the job that runs over. The total is compared with the money you have available, and divided by the project area for a cost per square foot that you can compare with local remodeling cost guides or contractor quotes.
- m
- Contractor markup rate
- t
- Sales tax rate
- c
- Contingency rate
Worked examples
Mid-range kitchen remodel
Line items add up to $46,500. Markup of 15% on the $43,000 of construction work is $6,450, and 7% tax on $23,000 of materials and fixtures is $1,610, giving $54,560. A 15% contingency adds $8,184 for a total of $62,744 — $313.72 per sq ft and $7,744 over the $55,000 available.
DIY bathroom refresh with no contractor
The items total $9,300 with no markup. Tax at 6% on $7,000 of materials and fixtures is $420, and a 10% contingency on $9,720 adds $972, for $10,692 — about $214 per sq ft and $1,308 under the $12,000 budget.
Basement finish with a general contractor
Items total $67,500. A 20% markup on the $63,000 of construction work is $12,600, and 8% tax on $28,000 of goods is $2,240, making $82,340. A 20% contingency (common for older basements) adds $16,468, for $98,808 or about $124 per sq ft.
Frequently asked questions
How much contingency should I add to a renovation budget?+
Most remodelers recommend 10–20% of the project cost. Use the low end for cosmetic updates in newer homes and 20% or more for older houses, kitchens and bathrooms where hidden problems such as rot, old wiring or plumbing are common. Keep it separate and only spend it on surprises.
What is a typical contractor markup on a remodel?+
General contractors commonly add 10–25% on top of their subcontractor and material costs to cover overhead (insurance, office, vehicles, supervision) and profit. Some quote it as a separate line, others build it into each item; ask so you do not count it twice.
How do I budget for a kitchen remodel?+
List every cost — demolition, cabinets, countertops, flooring, appliances, plumbing and electrical labor, permits and design — then add markup, sales tax and a 15–20% contingency. Cabinets and labor are usually the largest shares. Compare the total per square foot against local quotes before committing.
Is labor subject to sales tax on a renovation?+
In most US states, labor for remodeling real property is not taxed, but the materials and fixtures are, either paid by you or built into the contractor’s price. Rules vary by state, so check your state revenue department if the amount is significant.
Should I finance a renovation or pay cash?+
Paying cash avoids interest, but home equity loans, HELOCs and renovation loans let you spread the cost and keep emergency savings. Compare the interest cost with the project’s value; a home equity or home improvement loan calculator can show the monthly payment.
Results are estimates for educational purposes and are not financial advice. Rates, fees and terms vary — confirm with your lender or a licensed advisor before making decisions.