How we calculate our figures

Where the numbers come from

Our figures are computed from every published listing on PropertySights: condos and houses for sale and for rent in Bangkok. Nearly all of them (about 98%) are condos.

The figures refresh automatically. Our server recalculates them at most every 15 minutes, and pages pick up the new figures within another 15 minutes. A listing that is removed drops out of the figures as soon as the cache refreshes.

Asking prices, not sale prices

These are the prices owners are asking, not prices at which units sold or leased. Thailand does not publish unit-level transaction prices. Asking prices usually sit somewhat above what deals close at, especially for sales. For an official measure of transaction prices, see the Bank of Thailand price index on our statistics page; it is built from mortgage contracts.

Medians, not averages

We publish the median: the middle value once listings are sorted. An average is dragged by a handful of penthouses and by data-entry errors. For example, a monthly rent typed into the sale-price field produces an impossible ฿900/m² sale price. A median is barely moved by either.

Where we show a range, it is the middle half of listings: the 25th to 75th percentile. A quarter of listings are cheaper than the low end and a quarter dearer than the high end.

Price per square metre

For each sale listing with both a price and a unit size, price ÷ size. We take the median of those per-unit figures for an area or building, rather than dividing a total price by a total area, so one very large unit cannot dominate.

Minimum sample sizes

Below these counts we hide a figure rather than show a noisy one:

• Area figures (price per m², rent): at least 4 listings.
• Building figures (price per m², rent, yield): at least 3 listings.
• A row for one bedroom count, and any 25th–75th percentile range: at least 5 listings.
• Area comparison tiles and the Bangkok areas table: at least 20 listings.
• The Bangkok condo price index: at least 20 sale and 20 rent listings for an area's full row; areas with 10–19 on each side are shown without a yield.
• The rent estimate on a listing page: at least 5 comparable rentals in the same building, or in the area when the building has too few.
• City-wide charts on the statistics page: at least 50 listings per bedroom count.

Gross yield and net yield

Gross yield = monthly rent × 12 ÷ purchase price. We only compute it from units listed for sale AND for rent at the same time, so the price and the rent describe the same unit. Results outside 1–15% are discarded as data errors (we count how many), and we publish the median.

We do not publish net yield, because the costs that turn gross into net differ from owner to owner. To estimate it, subtract from the annual rent:

• the common-area (juristic) fee, usually charged per m² per month;
• the sinking fund, if one is due;
• months the unit sits empty between tenants;
• the agent's fee, typically one month's rent per one-year lease;
• land and building tax, insurance, and repairs and furnishing;
• income tax on the rent.

Known limits

• Our inventory is not the whole market: central, foreign-facing districts are over-represented, and the outer suburbs under-represented.
• Listing mix moves a median. If more luxury units come on in an area one month, its median rises even if no individual price changed.
• Unit size is as entered by the owner or agent, and is occasionally wrong; the median limits the damage.
• The Bank of Thailand condo index mixes new and resale units and is a 3-month moving average, so it turns slowly.
• Ministry of Interior population counts only people registered at an address. Foreigners and many tenants are registered elsewhere, so condo districts are undercounted.
• Government sources use Buddhist Era years (CE + 543); we convert them to CE on the English page.
• The unregistered population is an NSO survey estimate of people living in Bangkok without being registered there, not a headcount.
• NSO changed how it measures the average wage in 2024, so we only show wages from 2024 onwards and never compare them with earlier years.
• Company counts come from the Department of Business Development's monthly registers and place a company at its head office, which is not always where it operates. One month (March 2026) is missing from DBD's published files; quarters with a missing month are left out of the chart.

Official sources on our statistics page

We republish these series unchanged, apart from converting years and averaging daily exchange rates by month. Each chart links to its source.