The questions that sit behind the numbers — where the units come from, which conversions are exact, what a deed area really tells you, and how to compare prices quoted in different units. Each answer points to the page that covers it in full.
The figure isn't arbitrary — it falls out of the wah, a traditional Thai length unit. One wah is 2 metres, so one square wah is 4 square metres. A rai is fixed at 400 square wah, which makes 1,600 square metres exactly. Try it on the rai to square metres converter.
It depends on the plot and the buyer. Farmland, orchards and large plots outside town are discussed in rai; subdivided and urban plots are quoted in square wah. Ngan shows up on the title deed more often than in conversation. See the ratios on ngan to square metres and square wah to square metres.
The rai-ngan-wah system runs through the land register and every title deed, so changing units would mean reissuing the paperwork. Metric units mostly appear when Thai figures are compared with international data — see rai to hectares and rai to acres.
Everything between rai, ngan, square wah, square metres and hectares is exact, because each unit is defined as a whole number of square metres. The acre is the only one that isn't: it is 4,046.8564224 square metres, so any result involving acres is a rounded figure.
When a result is below 1 — converting 1 m² into rai, for example — the tool keeps extra decimals so the figure doesn't round away to zero. Results from 1 upwards use two decimals, and results from 1,000 upwards are shown as whole numbers.
Enter 0, or just leave the field empty — blanks count as zero. A deed reading 2-0-30 goes in exactly as written, with no need to fold the ngan into square wah first. Switch to rai-ngan-wah mode on the converter.
No. A full Chanote (Nor Sor 4 Jor) area comes from a survey tied to precise boundary markers, while lesser documents may rest on rougher measurements, so their figures carry more uncertainty. See Thai land title deed types and how to read a deed's area.
The deed, always. Its figure is what transfers and fee calculations are based on. Brochure numbers are often rounded to a tidy size, or include land that isn't inside that plot's deed. More in standard plot sizes in Thai housing estates and how to read a deed's area.
Put both on the same footing first. The land-value calculator on the home page takes a price per wah, per rai or per square metre and shows the per-rai and per-wah equivalents together, so two listings become directly comparable. For what drives each convention, see land price per rai vs. per wah.
No. Identical areas in different locations can differ enormously in price — road frontage, plot shape and zoning move the per-unit figure as much as size does. Converting units makes numbers comparable; it doesn't value them. More in land price per rai vs. per wah.
No. Land and building tax is worked out from the appraised value and how the land is used, not from the unit the area happens to be written in. Converting only makes the figure easier to read. See how Thai land and building tax is calculated.
No. Results are for preliminary reference only. They are not an official valuation, not financial advice, and no substitute for a survey carried out by Land Department officers.
Each common pair has its own page, with worked examples and a comparison table for that pair: rai to square wah · rai to hectares · rai to acres · ngan to square metres · square wah to square metres · square metres to rai · hectares to rai. Any other combination can be picked from the unit menus on the main converter.
It swaps the source and target units and carries the result over as the new input. So 5 rai = 0.8 hectares becomes 0.8 hectares = 5 rai after one press.
No. All conversion runs in your browser. Figures entered in the calculator are not sent to or stored on any server, and the site has no account or login.
Yes. Thai and Arabic numerals are both accepted, as are thousands separators like 1,200 — the input is normalised before the calculation runs.
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Enter a single unit or a full rai-ngan-wah deed figure — the result updates as you type.
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