How to Choose Real Estate Comps That Won't Lie to You

How to choose real estate comps that produce an accurate value

To choose real estate comps that won't mislead you, pull three to six recently sold properties within roughly the last 90 days, within about half a mile, that match your subject's bed/bath count, square footage (within ~20%), age, and condition tier—then adjust each comp for its differences before you settle on a value. Everything else in comp selection is refinement on top of that core rule.

Real estate comps (comparable sales) are the foundation of every accurate ARV, listing price, and max offer. Get them right and the rest of your underwriting has a solid base. Get them wrong—and it's easy to get them wrong—and every downstream number is fiction.

What actually makes a property "comparable"

A true comp mirrors the way a buyer or appraiser would substitute one property for another. Prioritize these attributes, roughly in order:

• Location — Same neighborhood, ideally the same subdivision or a few blocks away. Never cross a major road, school district line, or clear value boundary.
• Recency — Sold within 90 days. Stretch to 6 months only in low-volume markets, and adjust for price trends.
• Living area — Within about 20% of the subject's above-grade square footage. Basements and garages are valued separately, not lumped in.
• Bed/bath count and layout — A 3/2 rarely comps cleanly against a 4/1.
• Age and construction — A 1960s ranch and a 2015 build aren't substitutes even if the square footage matches.
• Condition — This is the one investors botch most. A gut-rehab-ready shell does not comp against a turnkey home unless you adjust hard for it.

Sold, not listed: use closed transactions

Active listings tell you what sellers hope to get. Closed sales tell you what buyers actually paid. Anchor your value to sold comps.

That said, actives and pendings still have a job:

• Pending sales hint at where the market is heading before those closings hit the record.
• Active listings show your future competition. If ten similar homes sit unsold at your target price, that's a warning regardless of what sold three months ago.

For a flip, sold comps set your ARV and pendings/actives set your exit risk. If you're building an after-repair value, walk through the full process in getting ARV right on a flip.

How to adjust comps line by line

No two properties are identical, so you adjust each comp toward the subject. Add value to the comp when it's inferior; subtract when it's superior. Common adjustments:

• Square footage — Use a supportable price-per-square-foot delta for your market (often $40–$100+/sq ft), not a blanket number.
• Bedrooms/bathrooms — A full bath commonly carries a few thousand dollars of value; an extra bedroom more, depending on the market.
• Garage, pool, finished basement — Each gets its own line.
• Condition — Estimate what it would cost to bring the comp to the subject's condition (or vice versa) and adjust by that.
• Lot size and view — Meaningful in some markets, negligible in tract subdivisions.

Rule of thumb: if total gross adjustments on a comp exceed about 25% of its sale price, that comp is too different—drop it and find a closer match.

Reject the outliers before they poison your average

One bad comp can swing your value by tens of thousands of dollars. Scrub for these:

• Non-arm's-length sales — Family transfers, estate sales, and transactions between related parties.
• Distressed sales — REO and short sales often close below market. If your area is saturated with them they become the market, but don't blend one lonely foreclosure into a stack of retail sales. If you're weighing distressed inventory, see short sale vs foreclosure buying dynamics.
• Concessions — A $300,000 sale with $12,000 in seller-paid closing costs is really a ~$288,000 sale.
• Statistical outliers — If five comps land between $290K and $310K and one shows $355K, that sixth sale had a story. Find it or exclude it.

A quick worked example

Say your subject is a 3/2, 1,500 sq ft ranch in average condition, and you pull:

• Comp A: 3/2, 1,550 sq ft, renovated — sold $320,000. Subtract ~$25,000 for its superior finishes → $295,000 adjusted.
• Comp B: 3/2, 1,400 sq ft, similar condition — sold $285,000. Add ~$5,000 for the 100 sq ft the subject has extra → $290,000 adjusted.
• Comp C: 3/1, 1,480 sq ft, similar condition — sold $278,000. Add ~$8,000 for the missing bathroom → $286,000 adjusted.

Three adjusted comps cluster around $286K–$295K, so a supportable value lands near $290,000—not the raw $278K–$320K spread you started with. The adjustments are what turn scattered sales into a defensible number.

Where comps go wrong—and how to protect yourself

The biggest mistakes are subtle:

• Comping condition to the wrong tier. Investors routinely value a fixer using turnkey comps. Your ARV assumes finished condition; your purchase math must reflect the current one.
• Reaching across value lines. Two streets apart can be two different markets.
• Cherry-picking the highs. Confirmation bias inflates every deal. Let the middle of the cluster lead.
• Stale data in a moving market. In a market shifting a percent or two a month, a six-month-old comp needs a time adjustment.

For a repeatable pull process, work through how to pull sales comps for a flip.

Let verified data do the heavy lifting

Manual comping is slow and biased toward whatever confirms the deal you already want. Modern analysis tools like PropertyWiz AI pull market-calibrated comps with statistical outlier rejection and pre-populate the value, rent, taxes, and other inputs from live, verified data—so your ARV starts from reality instead of a guess, and you go straight to the decision.

Good comps are a discipline, not a shortcut. Match the fundamentals, adjust honestly, throw out the outliers, and let the middle of the cluster—not your hopes—set the number.