Every estimate starts with what similar units nearby are asking right now. We search live listings across the major Canadian rental platforms and keep only genuine comparables: the same number of bedrooms and bathrooms, the same property type, and a similar size. A listing in the same building or on the same street counts for more than one across town, and listings from noticeably pricier or cheaper areas only help set the outer bounds of the range.
Because no two units are exactly the same size, comparable prices are adjusted before they're used. Rent doesn't scale linearly with square footage — smaller units rent for more per square foot — so the adjustment is deliberately partial. When a comparable is shown with "≈$X at your size," that's the adjusted figure.
If you use the renter-side check and tell us a listing's asking price, that price never reaches the estimator. The market estimate is computed first, on its own; the asking price is only compared against it afterwards to produce the verdict. The same rule applies on the landlord side: the number you have in mind is captured before your estimate is revealed and never shapes it.
The estimator also refuses to use the subject's own listing as evidence about itself. If your unit is currently advertised, that ad's price is detected and set aside — otherwise the tool would simply repeat whatever the ad says, which is useless for the one question that matters: "is this price right?"
Some comparables are marked "recorded on an earlier search." These are real listings from the usual sites — we simply saw them near this address within the last 45 days and kept them:
We also ask landlords what they listed a unit for, and we keep those answers — but we do not currently feed them into anyone else's estimate. With the number of confirmed rents we hold today, a single answer would carry far more weight over one estimate than a handful of data points deserve. We use them to check our own accuracy instead, and we'll revisit when there are enough of them to speak for a market rather than for one unit.
Confidence reflects the evidence, not our mood: it rises with the number of genuine comparables found — counting only listings that are evidence about this property, so the unit's own ad and listings we had already recorded nearby don't inflate it — is capped for houses (which have fewer and messier comparables than condos), is tempered when the unit's own live ad disagrees sharply with our number, and drops to the point where we publish no number at all when we can't pin the address to a specific building or can't find enough genuine comparables. The comparables behind every estimate are listed, so you can judge them yourself.
rentperch works for any Canadian address — from Vancouver and Toronto to Halifax and everywhere between. Dense condo markets produce the tightest ranges; smaller markets work too, with the confidence level saying how much evidence was found.