How the figures work
What every number on this site is based on, how it’s calculated, and what it can’t tell you. Journalists and researchers are welcome to quote it.
Where the prices come from
Two sources: anonymous reports from tenants about the rent they actually pay, and advertised (asking) prices from public ads on ikman.lk for rent, vehicles for sale and vehicle hire. From ads we store only facts (price, location, type, size or make, model and year), never ad text, photos or seller details. Every figure says how many reports and ads it is based on.
How fresh it is
Ads are collected twice a week and count while they were seen in the last 30 days; an ad that disappears is assumed sold or let. Tenant reports count for 3 years, by the year the rent was agreed. Every page shows when its ads were last updated.
How figures are calculated
We show the median (half of prices are below it, half above) and the middle half (the 25th to 75th percentile) rather than averages, so a few extreme prices can’t move the numbers much. Prices are rounded to Rs. 500, Rs. 5,000 or Rs. 50,000 depending on their size, so they never look more precise than the data.
Minimum sample sizes
Nothing is shown until there are at least 5 prices, and a row in a breakdown table needs at least 3. Advance payments and landlord conditions need at least 5 tenant reports. Pages without enough data are kept out of search results.
“Is it fair?” checks
A quote is compared with the narrowest group that has enough prices: for rent, the same area and type of place, then the same area, then the district (always the same number of bedrooms); for vehicles, the same model and year, then a year either side, then any year; for hire, the area, the district, then nationwide. Results say when a wider group was used. Under 90% of the median is “below typical”, up to 115% “about typical”, up to 140% “above typical”, and anything higher “far above typical”.
Keeping it honest
Each connection can send at most 5 tenant reports a day, and reports are checked against nearby prices: one more than 3 times, or less than a third of, the local median is held for review. Vehicle hire ads priced per kilometre, per month or for weddings are left out, as are ads without a usable price.
Limitations
Asking prices are what sellers hope for; the price finally agreed is often lower. Agents sometimes post the same property or vehicle several times, and those ads may be counted more than once. Vehicle prices aren’t adjusted for condition, mileage or options. Areas with few ads, and most districts outside the Western Province, have much less data.
Using these figures
You’re welcome to quote and chart these figures. Please cite “WTF Sri Lanka (wtfsrilanka.com)”, say whether you are quoting asking prices or reported rents, and give the date. Every comparison can be downloaded as a CSV file.