Not to be confused with the dye and food additive Catechu and the tree from which it is made Senegalia catechu
Katha or Biswa (also spelled kattha or cottah; Hindi: कट्ठा, Assamese: কঠা, Bengali: কাঠা) is a unit of area mostly used for land measurement in India, Nepal, and Bangladesh. After metrication in the mid-20th century by these countries, the unit became officially obsolete. But this unit is still in use in much of Bangladesh, Northern India, Eastern India and Nepal. The measurement of katha varies significantly from place to place.
In Purvanchal, 1 Katha = 1,361.25 square feet (126.464 m2) or 151.25 square yard. One Bigha is made up of 5 to 20 Katha. Katha is divided into 20 Dhur and Dhur is subdivided into 20 Dhurki.
Bangladesh
In Bangladesh, one katha is standardized to 720 square feet (67 m2), and 20 katha equals 1 bigha.
In Assam, 1 Katha is equal to 2,880 ft2 and 1 Bigha = 5 Katha; 1 bigha = 14,400 ft2 and in lower assam such as cachar it is 720sq.ft
Bihar
In Bihar, one Katha may vary from 720 to 3,267 square feet (ft2). 1 Bigha = 20 Katha. One katha is divided in 20 dhur. One dhur is subdivided in 20 dhurki. The origin of the term and measurement unit was during the Pala Empire.[1] 1 Decimal = 435.6 square feet & 1 Acre = 100 decimal.[2][3]
In Bettiah, 1 Katha = 7.5 decimal = 3,267 ft2 and 1 bigha = 65,340 ft2
In Chhapra, 1 Katha = 4 decimal = 1,742.4 ft2 and 1 bigha = 34,848.0 ft2
In Hajipur, 1 Katha = 1,901.25 ft2 and 1 Bigha = 38,025 ft2.
Jharkhand
In Jharkhand, 1 Katha ranges from 720 to 1,742 square feet. In Ranchi, 1 Katha is equal to 720 ft2. 1 bigha is equal to 20 Katha; 1 bigha = 14,400 ft2.
Punjab
In Punjab and Haryana, Katha is known as Biswa. 1 Bigha = 20 Biswa and 1 Biswa = 20 Biswansi.
In Uttar Pradesh, Katha is also known as Biswa. One Katha is equal to 1,361.25 ft2 or 151.25 square yard or 126.46 square metre. One Bigha in UP can range from 5 to 20 Katha.