Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Better financial move
Repair
Estimated years of roof life left
4
Repair path total cost
$2,400
Replace path amortized cost
$2,545
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter repair cost ($).
- 2Enter full replacement cost ($).
- 3Enter current roof age (yrs).
- 4Enter typical roof lifespan (yrs).
- 5Enter expected repairs before replacement needed.
- 6Read your better financial move on the right — it updates as you type.
- 7Hit Share to keep the scenario or send it to someone.
About this calculator
A roof repair buys time cheaply but a roof nearing the end of its life may need multiple repairs before a full replacement becomes unavoidable anyway. This tool compares a single repair cost against replacement cost, spread over the roof's remaining useful life, and estimates how many repair cycles you're likely to pay for before replacement is forced regardless.
Worked example
Using the values the calculator loads with:
Inputs
- Repair cost: 1200 $
- Full replacement cost: 14000 $
- Current roof age: 18 yrs
- Typical roof lifespan: 22 yrs
- Expected repairs before replacement needed: 2
Results
- Better financial move: Repair
- Estimated years of roof life left: 4
- Repair path total cost: $2,400
- Replace path amortized cost: $2,545
What each field means
Inputs
- Repair cost ($)
- The repair cost used in the calculation, measured in $. Starts at 1200 $ so you have a working example on load.
- Full replacement cost ($)
- The full replacement cost used in the calculation, measured in $. Starts at 14000 $ so you have a working example on load.
- Current roof age (yrs)
- The current roof age used in the calculation, measured in yrs. Starts at 18 yrs so you have a working example on load.
- Typical roof lifespan (yrs)
- The typical roof lifespan used in the calculation, measured in yrs. Starts at 22 yrs so you have a working example on load.
- Expected repairs before replacement needed
- The expected repairs before replacement needed used in the calculation. Starts at 2 so you have a working example on load. Accepted range: 1–10.
Results
- Better financial move
- Returned as a plain value and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Estimated years of roof life left
- Returned as a whole number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Repair path total cost
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Replace path amortized cost
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How many repairs are typical before a roof needs full replacement?
Once a roof passes about 80% of its rated life, most roofers see 2-3 targeted repairs (flashing, isolated shingle sections) before wide-spread failure forces a full tear-off.
Does insurance change this math?
Yes — storm-damage claims can cover full replacement even on an older roof, which usually makes replacement free or near-free relative to a self-funded repair.
Should I replace before selling my house?
If the roof is past 75% of its life, buyers and inspectors will flag it; replacing beforehand can be cheaper than the price concession a buyer will negotiate.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Repair vs Replace Roof Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/repair-vs-replace-roof
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/repair-vs-replace-roof" target="_blank" rel="noopener">Repair vs Replace Roof Calculator — RevenueLab</a> (2026).</p>
Source: [Repair vs Replace Roof Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/repair-vs-replace-roof) (2026).