Planning · Home renovation
Renovation budget calculator.
Add your estimate, allowances and fees, put a contingency on top, and see how much of it is left as the job moves.
Inputs
Your budget
Enter the numbers above.
How this works
Your renovation budget is the contract price plus everything the contract does not fix, plus a reserve for surprises. This calculator adds your base estimate, the allowances written into the contract and your permit and design fees, then puts a contingency percent on top of that subtotal. Total = (base + allowances + fees) x (1 + contingency / 100). Then it tracks how much of the reserve is gone: an allowance that ran over, plus any approved change orders, comes out of the contingency.
The 10 to 20 percent reference is HUD's range for the contingency reserve on FHA 203(k) rehabilitation loans for homes 30 years or older (see sources). It is a useful benchmark, not a rule for your project; older homes with hidden systems deserve the high end, a new-build addition with a fixed-price contract may need less.
Worked example. Base estimate $60,000, allowances $8,000, fees $3,000: the subtotal is $71,000. A 15 percent contingency is $10,650, so the total budget is $81,650. If the allowances actually cost $9,500, that is $1,500 over, and with $2,000 of approved change orders the contingency used is $3,500, leaving $7,150 (67 percent) in reserve.
Frequently asked questions
How much contingency should I add to a renovation budget?
There is no single published rule for every project. HUD sets a 10 to 20 percent contingency reserve for FHA 203(k) loans on homes 30 years or older, which many owners use as a reference range. Older homes and projects that open up walls lean to the high end.
What is an allowance in a renovation contract?
An allowance is a placeholder amount in the contract for something not yet chosen, such as tile or fixtures. If your final choice costs more than the allowance, you pay the difference, so track it against the budget.
Is contingency the same as a change order?
No. Contingency is your own reserve. A change order is a written change to the contract scope and price. Approved change orders are usually paid from the contingency, which is how this calculator treats them.
Should I tell my contractor about my contingency?
That is your call. The contingency is a planning number for your own finances, not part of the contract price.
Sources
Checked
- HUD, FHA Single Family Housing Policy Handbook 4000.1 (PDF), 203(k) Rehabilitation Mortgage Insurance Program, "Standard 203(k) Financeable Contingency Reserve", opened 8 October 2026. the copy opened carries a transmittal effective 15 October 2019, so check HUD for the current text. Says a contingency reserve covers unforeseen project costs and, for structures 30 years or older, is required at a minimum of 10 percent and a maximum of 20 percent of the financeable repair and improvement costs
Runs entirely in your browser. Nothing you type is sent or stored.
Planning note
Estimates only, not financial, legal or professional advice. You supply every price; this page contains no regional cost data. Confirm real costs with written quotes from licensed local contractors.