West Bengal land measurement units — katha, bigha, decimal, satak

The conversions, and where they come from

The Bengal units were standardised under British administration, so within West Bengal the conversions are settled: 1 bigha = 20 katha = 14,400 sq ft (1,600 square yards), which makes 1 katha = 720 sq ft, and 1 katha = 16 chatak, so 1 chatak = 45 sq ft.

You can corroborate the katha figure from the law rather than from a blog. The West Bengal Land Reforms Rules and the L&LR Manual cap homestead settlement at *"5 cottahs (.0335 hectare)"* — and 0.0335 hectare divided by five works out to 721 square feet. The government is treating a cottah as 720 sq ft.

Separately, the survey units the record system itself runs on are fixed by definition. The acre is a standard unit and the decimal — what Bengali usage calls a satak — is one-hundredth of an acre, so 1 decimal = 435.6 sq ft. Land records work in these, which is why your Khatian is unlikely to be written in katha at all.

What each unit actually is

It helps to separate the units by where they come from, because that predicts how much you can trust a conversion involving them.

• Acre — a standard unit, the same everywhere. Land records and survey documents work in it.
• Decimal / satak — one-hundredth of an acre. This is definitional, not local: a decimal is a decimal in every district. Bengali usage says *satak*; the record may print *decimal*. They are the same unit and it is common to see a recorded area given this way.
• Bigha — the largest of the customary Bengal units, standardised at 14,400 sq ft. The Bengal bigha differs from the bigha used in other Indian states, which is the source of most conversion errors.
• Katha / cottah — one twentieth of a bigha, so 720 sq ft. Written *cottah* in older documents and in much legal drafting.
• Chatak — one sixteenth of a katha, so 45 sq ft. Used for small areas, chiefly urban and homestead plots.
• Square feet — standard, and increasingly how urban plots and flats are quoted, which is why so many people arrive needing to convert into it.

Where conversions actually go wrong

The failure mode is almost never the arithmetic. It is applying a bigha from somewhere else. The bigha is a customary unit that was standardised separately in different regions, so the Bengal bigha of 14,400 sq ft is simply a different area from the bigha used in Bihar, Assam or Uttar Pradesh. A national conversion calculator that does not ask which state you are in will mislead you.

You will also find West Bengal pages quoting a katha of 360 square feet, usually attached to Kolkata. That figure is contradicted by the government's own homestead equivalence, and the sites carrying it tend to contradict themselves elsewhere on the same page. Treat it as unreliable.

The more consequential problem is a different one: the area someone quotes you in katha and the area recorded against the dag are two different claims, and only one of them governs.

Quick reference

The figures for West Bengal, in one place.

• 1 bigha = 20 katha = 14,400 sq ft = 1,600 sq yd
• 1 katha (cottah) = 16 chatak = 720 sq ft
• 1 chatak = 45 sq ft
• 1 acre = 100 decimal (satak) = 43,560 sq ft; 1 decimal = 435.6 sq ft
• 1 acre ≈ 3.025 bigha — the awkward ratio is why records use acres and decimals rather than bigha
• Not transferable across states: a bigha figure from a national calculator or a non-Bengal source
• Ask a local source: your BL&LRO office, a local surveyor (amin), or the registration office deal in local usage every day and will tell you what the terms mean where your land is. Note that an amin's measurement is a practical guide, not a legal determination — it carries no official standing unless the amin was appointed by a court or by the L&LRO.

The figure that actually governs: your recorded area

Here is the practical resolution to all of the above, and it is simpler than the conversion question suggests. If you do not have the recorded figure to hand, looking up a Khatian is a short job once you have a banglarbhumi.gov.in account — which you will need, because the portal does not return a record to a signed-out visitor.

For any purpose that matters — a sale, a mutation, a partition, a loan, a khajna assessment — the operative area is the area recorded against your dag number in the land record, in the unit the record uses. Not a conversion you performed. Not the figure quoted in an advertisement. Not what the seller's family has always said the plot measures.

You can read that recorded area yourself, once you are signed in. On banglarbhumi.gov.in, Know Your Property is the main search — select District, Block and Mouza, then look the plot up by dag number or by khatian number. RS-LR Plot Information shows how the plot reads across record generations, which matters if your figure came from an older document. Both open from the menu while signed out and both will let you work down the dropdowns, but the request that returns the area is answered with the sign-in page. Register before you start.

If the recorded area and the area you were told differ materially, that discrepancy is the finding — not something to resolve by choosing whichever conversion makes the numbers agree. A small difference between survey generations is ordinary. A large one is a question for the BL&LRO, and if a transaction is involved, for an advocate who does land title work.

Where the conversion question comes from, and what to do about it

Most people arrive at this question from one of three situations, and the right next step differs in each.

Buying or selling. The area in the deed and the area in the record should be reconciled before money moves. Quote the recorded figure, in the recorded unit, in the document. Converting to katha for negotiation is fine; converting for the paperwork is where errors become expensive.

Dividing among heirs. A partition among co-sharers works from the recorded area and each holder's recorded share. Note that a share on a Khatian is expressed as a fraction — an undivided interest in the plot, not a marked-out piece of ground — so converting a share into katha does not tell you which katha. Physical division is a separate process.

Comparing a listing to reality. Urban listings quote square feet, rural talk quotes bigha and katha, and the record quotes decimals. That is three vocabularies for the same land. Pull the record, work from it, and treat the other two as approximations of it.

For any of these, checking the recorded area is a small task you can do from a phone. The portal's lookups work in a mobile browser, with a banglarbhumi.gov.in account. Bhumir Tathya is our own app — free, unofficial, Android — which presents those same lookups in Bengali and English and keeps records you have already viewed readable offline, which is handy when you are standing on a plot with no signal comparing what you were told against what is recorded. It does not bypass any government authentication or fee — you still need your own portal account — and a saved record shows the record as it stood when you viewed it, so re-check it on the portal before relying on it for a transaction.