How to Comp a Property: A Step-by-Step Guide
Updated June 17, 2026
Comping a property means estimating its value from recent sales of similar homes nearby. The process: pull three to five sold comps within half a mile and six months, match them on size, beds, baths, and condition, adjust for differences, then derive a value. Good comping uses closed sales — never active listings — and stays inside the subject's true neighborhood, not a better one.
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Comping is the single most-used skill in real estate investing, and the one most people do sloppily. A bad comp set produces a confident-looking number that's simply wrong — and an offer built on a wrong number is a loss waiting to happen.
The good news: comping is a repeatable process, not an art. Follow the same steps every time — pull, filter, adjust, reconcile — and your numbers get tighter and faster. This guide walks the full sequence the way investors run it before sending an offer.
Step one: pull the right comps
Start with sold properties, because only a closed sale proves what a buyer actually paid. Active listings show asking prices, which are negotiating positions, not facts. Pending sales are a clue but not yet confirmed. Your foundation is always the closed comp.
Set your filters tight to start: sold within six months, within half a mile, same property type, within roughly 20% of the subject's square footage, and the same bed/bath count. You can loosen these later if you can't find enough, but begin narrow. A tight initial filter forces you to confront how thin or thick the data really is.
Step two: adjust for differences
No two properties are identical, so you adjust. If a comp has a third bathroom the subject lacks, subtract its value from the comp's price. If the subject has a finished basement the comp doesn't, add for it. The goal is to restate each comp as if it were the subject, then compare.
Adjustments are where judgment enters. You won't have a perfect dollar value for every feature, so use market reason: a garage, an extra bedroom, lot size, a renovated versus dated kitchen. Be consistent and be conservative — when you're unsure whether an adjustment helps or hurts, lean toward the figure that protects your downside.
| Feature difference | Adjustment direction | Typical basis |
|---|---|---|
| Extra bedroom | Subtract from comp | Local price-per-bedroom data |
| Extra full bath | Subtract from comp | Cost plus market premium |
| Finished basement | Subtract from comp | Partial sq-ft value |
| Larger lot | Subtract from comp | Land value in that block |
| Renovated vs dated | Subtract from comp | Cost of the rehab to match |
Common comp adjustments and how to treat them
Step three: reconcile to a value
After adjusting, your comps should cluster around a range. Don't just average them — weight the ones most similar to the subject most heavily. A comp two doors down that's nearly identical tells you more than one half a mile away that needed three big adjustments.
If the comps scatter widely instead of clustering, that's a signal: either your filters were too loose, the neighborhood is genuinely inconsistent, or you've crossed an invisible boundary like a school zone or a busy road. Tighten and re-pull rather than forcing an average over noise.
Comping at scale, then making the offer
Comping one property is a careful manual exercise. Comping a thousand to feed an offer campaign is a different problem — you can't hand-adjust every record. At scale you define a buy-box formula (a percentage of ARV, a fixed discount, a cap-rate floor) and apply it across a list, accepting that automated comps are looser than hand comps and pricing in that margin.
That's the bridge from analysis to action. Once each property on a list is comped against your formula, BILT CRM generates and blasts the corresponding LOIs to listing agents automatically. The comping you'd do by hand on one deal becomes the engine that puts hundreds of priced offers into the market.
Frequently asked
What does it mean to comp a property?
Comping means estimating a property's value by comparing it to similar homes that recently sold nearby. You pull closed sales, match them to the subject on size, beds, baths, and condition, adjust for differences, and reconcile to a value. It's the foundation of every offer an investor makes.
Should I use active listings or sold comps?
Sold comps, always, for the value itself. A closed sale proves what a buyer actually paid; an active listing only shows what a seller hopes to get. Active listings can hint at current competition and direction, but never base your value on an asking price.
How far away can a comp be?
Start within half a mile and loosen only if you must. Value can change sharply across a school-zone line, a busy road, or a subdivision boundary, so distance alone is misleading. A comp a mile away in the same tract can beat one a few blocks away across a hard boundary.
How do I comp a property with no recent sales nearby?
Widen one filter at a time — first the time window, then distance, then property type — and document how far you stretched. Each loosening adds uncertainty, so build a bigger margin into your offer. In data-thin markets, conservative is the only safe posture.
The takeaway
Comping is a four-step discipline: pull closed sales, filter tight, adjust each comp to mirror the subject, and reconcile by weighting the closest matches. Sold comps only, real neighborhood boundaries, conservative adjustments. Do it by hand on one deal — then let BILT apply your buy-box formula across a whole list and turn the comps into offers in the market.