ARV Calculator
After-repair value from your comps — as a range, with the disagreement between them shown rather than averaged away.
The subject property
Enter the size the property will be after the rehab, including any square footage you are adding.
3 comparables
$165.71/sf · -2.78% size vs subject
$163.16/sf · 5.56% size vs subject
$160.61/sf · -8.33% size vs subject
Adjustment is a net dollar figure: positive when the comp is worse than your subject, negative when it is better. A comp with a finished basement yours will not have takes a negative adjustment.
Estimated ARV
$293,684
Range $289,091 to $298,286 across 3 comparables
Reconciliation
| 412 Maple | $298,286$165.71/sf |
|---|---|
| 1207 Oak | $293,684$163.16/sf |
| 88 Birch | $289,091$160.61/sf |
| ARV at median $/sf | $293,684 |
| ARV at mean $/sf | $293,687 |
| Range | $289,091 – $298,2863.13% spread |
| Agreement between comps | 1.28%Under 15% is tight; above it, treat the estimate as a range |
| Naive average of sale prices | $287,667Ignores size — shown only for contrast |
An estimate from the comparable sales you entered, not an appraisal or a broker price opinion. A licensed appraiser adjusts each comparable for condition, location, lot, layout and date of sale — this tool adjusts only by size and by whatever net adjustment you enter yourself. Do not rely on it as a valuation.
The most consequential number in a flip is also the least reliable
Everything downstream of after-repair value inherits its error. The maximum offer is a function of ARV. The loan amount is a function of ARV. The projected profit is ARV minus everything else. Get it wrong by ten percent on a $400,000 property and you have wiped out the entire margin on a deal that looked fine in the spreadsheet.
Which is why it is strange that most ARV calculators take three sale prices, average them, and return a single number to the dollar. That number carries a precision the method cannot support, and the false confidence is the actual danger — not the arithmetic.
Appraisers do not average. They adjust each comparable toward the subject — for condition, location, lot, layout, date of sale — and then reconcile, weighting the comps they trust most. The reconciled answer is a judgement, and a competent appraisal shows its work rather than presenting one figure as fact.
This tool cannot make those judgements for you. What it can do is stop hiding the uncertainty. Three things here that a plain average does not give you:
- A range, not a point. Each comp implies its own value for your subject. The spread between the lowest and highest is real information about how confident you should be.
- The median alongside the mean. One recently flipped, fully renovated sale will pull an average up hard and barely move a median. When the two diverge, one of your comps is doing too much work.
- A disagreement measure. If the comps vary more than about 15 percent around their own average, no single number is trustworthy, and the tool says so rather than quietly returning one.
There is also a contrast row showing the naive average of the raw sale prices. When your comps differ in size, that figure and the per-square- foot estimate come apart — which is the clearest demonstration of why size normalisation matters at all.
A practical note on pulling comps: sold, not listed. Within half a mile, and not across a line that changes schools or flood zones. Within three to six months. Within roughly 20 percent of your finished square footage. Same style and story count. Four comps that meet those tests beat ten that do not, and the tool will flag the ones that are too different in size to carry weight.
Once you have a defensible ARV, the next question is what you can pay for the property. That is the maximum allowable offer calculator.
Methodology
- Adjusted price = sale price + your net adjustment, floored at zero.
- Price per square foot = adjusted price ÷ the comp’s square footage.
- Indicated value = that price per square foot × your subject’s finished square footage. Each comp produces its own.
- ARV at median = median price per square foot × subject size. The headline figure.
- Spread = (highest indicated value − lowest) ÷ the median estimate.
- Agreement = standard deviation ÷ mean of price per square foot, as a percent. Flagged above 15 percent.
Comps with no square footage are ignored rather than dividing by zero. Size mismatch is flagged past 25 percent difference from the subject. Currency is computed in exact integer cents; the statistics are derived from exact values and only converted to floating point for the final square root.
Not modelled: condition, location quality, lot size, layout, date of sale, seller concessions, or market direction between the comp’s sale and yours. Those are exactly what an appraiser is for, and their absence is why the range matters more than the midpoint.
Frequently asked questions
- What is ARV in real estate?
- After repair value — what a property will be worth once the renovation is finished, not what it is worth today. Every other number in a flip hangs off it: the maximum offer, the loan amount, the projected profit. It is also an estimate about a sale that has not happened yet, which is why treating it as a single precise figure is the most common way a flip goes wrong on paper before it goes wrong in reality.
- How many comparable sales do I need?
- At least three, and this tool flags you when you have fewer. One sale is an anecdote and two cannot tell you which of them is the outlier. Appraisers use three as a floor for the same reason. More helps, but only if they are genuinely comparable — a fourth comp half a mile away in a different school district makes the estimate worse, not better.
- Why does this show the median rather than the average?
- Because one renovated flip in your comp set will drag an average badly and barely move a median. If three comps sit near $163 per square foot and a fourth sold at $239 after a full gut, the mean says your property is worth substantially more than any normal sale in the neighbourhood supports. The median ignores it. Both are shown so you can see the gap, which is itself informative.
- What counts as a good comp?
- Same neighbourhood, ideally within half a mile and not across a boundary that changes schools or flood zones. Sold within the last three to six months. Within roughly 20 percent of your subject's finished square footage — this tool warns you past 25 percent. Similar style and story count, and similar bed and bath configuration. A sold comp beats an active listing every time, because a listing is an asking price and asking prices are opinions.
- What does the agreement percentage mean?
- It is how much the comps vary around their own average, in percentage terms. Under 15 percent means they tell a consistent story and the estimate is worth something. Above it, they are disagreeing enough that a single number is false precision — usually because one comp is not really comparable, or because the area genuinely contains two different kinds of house.
- Can I use this instead of an appraisal?
- No. An appraiser adjusts every comparable for condition, location, lot size, layout, date of sale and financing concessions, then reconciles them with judgement about the local market. This tool adjusts for size and for whatever net adjustment you enter yourself. It is a fast, honest first pass for deciding whether a deal is worth pursuing — not a valuation, and no lender will accept it as one.
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