Land measurement

How many square feet is 1 katha?

Katha is the sub-unit of the bigha, so it inherits the bigha’s state-by-state disagreement — and the number of katha per bigha changes too.

1 katha is 720 square feet in West Bengal, 1,361.25 square feet in Bihar and 2,880 square feet in Assam. The unit is defined as a fraction of the local bigha: 20 katha to a bigha in West Bengal and Bihar, but only 5 katha to a bigha in Assam. That is why an Assamese katha is four times a Bengali one even though both states call it the same thing.

Worked out 2026-09-10 (IST) · State revenue-department and local-practice conversions

1 katha by state

Katha converted, by state
State	Katha per bigha	Square feet	Square metres	Gaj
West Bengal	20	720	66.9	80
Bihar	20	1,361.25	126.5	151.25
Jharkhand	20	1,360.55	126.4	151.17
Assam	5	2,880	267.6	320
Odisha (decimal system)	—	435.6 (uses cent)	40.5	48.4
Madhya Pradesh	20	600	55.7	66.67

Check the record, not the internet. Bigha, katha, gaj and cent are customary units, not units defined by the Legal Metrology Act. The conversion that binds you is the one printed on the local revenue record — the khasra, khatauni, RTC or 7/12 extract — and it can differ from the district figure by a few per cent. Use the numbers here to sanity-check a broker’s claim, and the revenue record to sign anything.

Common plot sizes in katha

Katha to square feet, for the three main definitions
Katha	West Bengal (720 sq ft)	Bihar (1,361.25 sq ft)	Assam (2,880 sq ft)
1	720	1,361.25	2,880
2	1,440	2,722.50	5,760
3	2,160	4,083.75	8,640
5	3,600	6,806.25	14,400
10	7,200	13,612.50	28,800
15	10,800	20,418.75	43,200
20	14,400	27,225.00	57,600

The formula

katha → square feet = katha × (local bigha in sq ft) ÷ (katha per bigha)

West Bengal = katha × 14,400 ÷ 20 = katha × 720

Bihar = katha × 27,225 ÷ 20 = katha × 1,361.25

Both terms in that first line vary by state, which is why katha is the Indian land unit most often mis-stated in listings.

Check your own numbers

Convert katha, bigha, acre and square feet without having to remember which state uses which divisor.

Area ConverterEvery Indian and metric land unit, converted in both directions.

Frequently asked

How many katha make 1 bigha?

Twenty katha in West Bengal and Bihar, five katha in Assam, and twenty in most of Jharkhand and Odisha. The count is part of the local definition, so it has to be looked up alongside the bigha size rather than assumed.

How many katha in an acre?

At the West Bengal katha of 720 sq ft, an acre is 60.5 katha. At the Bihar katha of 1,361.25 sq ft it is 32 katha exactly. In Assam, at 2,880 sq ft, an acre is 15.13 katha.

What is a chatak, and how does it relate to katha?

A chatak is one sixteenth of a West Bengal katha, so 45 sq ft. Kolkata property documents often express an area as so many katha, so many chatak and so many square feet, in the same way a length might be given in feet and inches. Sixteen chatak make one katha.

Is katha the same as kattha or cottah?

Yes - katha, kattha, kotha and cottah are transliterations of the same unit. Older Kolkata deeds and British-era records spell it "cottah" and use the same 720 sq ft value that is in use today.

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