How to Find Real Estate Comps: 7 Methods That Actually Work
Pulling comps is easy. Pulling comps that survive an appraiser, a buyer's agent, and a skeptical seller is the actual skill.
Short answer
To find real estate comps: search recent sold properties within roughly one mile, sold in the last three to six months, within ±20% of the subject's square footage, of the same property type and school zone. The MLS is the most reliable source; county records, listing aggregators, and automated comp tools fill the gaps when you lack MLS access.
The seven sources, ranked by reliability
1. The MLS (best available)
Confirmed sale prices, days on market, concessions, condition notes, photos, and price-change history in one place. If you have access, everything else on this list is a supplement. The limitations are real though: MLS coverage stops at market boundaries, off-market and new-construction sales frequently never appear, and data entry quality varies by the agent who typed it in.
2. County assessor and recorder records
The legal record of what actually transferred. Free, authoritative on price and date, and the only source that covers off-MLS transactions. What you do not get: condition, photos, concessions, or any indication of whether the sale was arm's length. In non-disclosure states (Texas, Utah, Idaho, Kansas, Louisiana, Mississippi, Missouri, Montana, New Mexico, North Dakota, Wyoming, Alaska), sale prices are not recorded at all.
3. Listing aggregators (Zillow, Redfin, Realtor.com)
Broad coverage, free, and genuinely useful for a fast look. They are also the noisiest source: stale records, sales that never closed, square footage pulled from tax rolls that disagrees with the MLS, and no concession data. Fine for screening, weak as evidence. We covered the deeper accuracy question in MLS data vs. public listing aggregators.
4. Automated comp reports
Tools that pull comps, adjust, and produce a formatted document. The trade you are making is speed for control — you get a client-ready deliverable in minutes, and you accept the tool's comp selection logic unless you can override it. Worth it for volume; worth verifying before it goes in front of a seller.
5. Appraisers you know
Not a data source so much as a sanity check. An appraiser who works your market daily will tell you in ninety seconds whether your comp set is defensible. This is the cheapest quality control available and almost nobody uses it.
6. Other agents
Off-market and pocket-listing sales that never hit the MLS live in agents' heads. A brokerage that shares this internally has a real data advantage over one that does not.
7. Your own closed files
You know exactly what condition those properties were in, what concessions were paid, and why the number landed where it did. Nobody else's dataset has that.
The screening rules
Once you have candidates, most of them need to go. Screen in this order:
- Sold, not listed. Active prices are competition, not evidence.
- Arm's length. Cut foreclosures, short sales, REO, family transfers, and anything with a suspiciously round number and a same-day deed.
- Recency. 90 days ideal, 180 acceptable, beyond that adjust for market movement and disclose it.
- Proximity. Same subdivision beats same mile beats same ZIP. Never cross a school attendance boundary without adjusting.
- Size band. ±20% square footage. A 1,400 sq ft comp for a 2,400 sq ft subject is not a comp with an adjustment — it is a different product.
- Type and era. Single-family to single-family. 1960s ranch to 1960s ranch.
- Condition. Look at the photos. Every time. This is where most bad comps get caught.
How many comps do you need?
Three to six. Below three you have no way to see an outlier. Above six you are almost certainly including properties that need paragraphs of explanation, and each one pulls your estimate toward the market average rather than toward this specific house.
If you cannot find three genuine comps, that is information. Either your search parameters are too tight, or the subject property is unusual enough that the comparison approach is weak and you should say so to the client.
Comp search parameters by market type
| Market | Radius | Time window | Notes |
|---|---|---|---|
| Dense urban | 0.25–0.5 mi | 3 months | Value changes block to block; stay tight |
| Suburban tract | 0.5–1 mi | 3–6 months | Same subdivision is nearly always available |
| Mixed suburban | 1 mi | 6 months | Watch school zone boundaries carefully |
| Rural | 3–10 mi | 12 months | Adjust for acreage and market drift; expect fewer comps |
| Condo / attached | Same building or complex | 6–12 months | HOA fee differences matter more than distance |
Red flags in a comp set
- Every comp supports the number the seller wanted. That is not analysis, that is confirmation.
- The price-per-square-foot spread across your comps exceeds 25%. Something is wrong with the set.
- A comp sold twice in eighteen months at very different prices — usually a flip, and the first sale is not a comp.
- Zero days on market with a below-trend price. Often an off-market deal to a known party.
- Sale price is suspiciously identical to a nearby comp. Check for a builder closeout or a bulk transfer.
What to do when there are no good comps
Unusual properties — the only 5-acre lot in a tract neighborhood, the converted church, the house with the accessory dwelling unit — break the comparison approach. Options:
- Widen the geography and adjust for location explicitly.
- Go back further in time and adjust for market movement using absorption and price trend data. See absorption rate.
- Use a cost approach for the unusual component (what does an ADU cost to build, minus depreciation) and comp the rest.
- Tell the client the range is wider than usual and explain why. Clients handle uncertainty better than they handle being wrong.
The bottom line
Finding comps is a filtering problem, not a search problem. Every source on this list will hand you twenty candidates in a minute. The value you add is deciding which four of them describe this house — and being able to say out loud why the other sixteen do not.
Once you have the set, the next step is adjusting it: how to adjust comps without guessing.
Frequently asked questions
How do I find comps for a house for free?
County assessor and recorder websites publish sale records free in disclosure states. Zillow, Redfin, and Realtor.com show recent sold data free but with lower reliability. The MLS remains the most complete source and requires licensed access.
How recent do comps need to be?
Within three to six months is standard. Beyond six months you should adjust for market movement in the interval and disclose that adjustment; beyond twelve months the comp is describing a different market.
How far away can a comp be?
Under a mile in suburban markets, a quarter to half mile in dense urban areas, and up to several miles in rural markets. Distance matters less than staying inside the same school attendance zone and micro-market.
Can I use active listings as comps?
Not as valuation evidence. Active listings show what sellers are asking, not what buyers have paid. They are useful for competitive positioning and for setting a practical ceiling on your list price.
What is a bad comp?
Any non-arm's-length sale (foreclosure, short sale, family transfer), a property in materially different condition with no adjustment, a different property type, a sale outside the school zone, or a comp more than roughly 20% different in square footage.
Do comps include concessions?
MLS records usually capture seller concessions; public records generally do not. A recorded sale price with substantial seller-paid costs behind it overstates the true market price and should be adjusted downward.