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.

• 1 Katha (কাঠা) = 720 sq. feet = 66.88 sq. metre = 1.652 Decimal (শতাংশ/ শতক)
• 1 Bigha (বিঘা) = 20 Katha (কাঠা) = 14,400 square feet = 1338 sq m = 1,600 sq yard
• 1 Acre (একর) = 3.025 Bigha (বিঘা) = 60.5 Katha (কাঠা) = 4,047 square metre
• 1 Hectare (হেক্টর) = 2.47 Acre (একর) = 7.475 Bigha (বিঘা) = 149.5 Katha (কাঠা)

India

Assam

In Assam, 1 Katha is equal to 2,880 ft² and 1 Bigha = 5 Katha; 1 bigha = 14,400 ft².

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 Patna & Arrah, 1 Katha is equal to 1361.25 ft² or 3.125 decimal.^[4]
  • 1 Hectare = 3.95 bigha = 79 Katha
  • 1 Acre = 1.6 bigha = 32 Katha
  • 1 Bigha = 27,225 ft² = 20 Katha
  • 1 Katha = 1,361.25 ft² = 20 dhur (Patna)
  • 1 Dhur = 68.0625 ft² = 20 Dhurki
• 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 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.

• 1 Acre = 2 bigha = 4,840 square yard
• 1 Bigha = 2,420 square yard
• 1 biswa = 121 square yard
• 1 biswansi = 6.05 square yard

Uttar Pradesh

In Uttar Pradesh, Katha is also known as Biswa. One Katha is equal to 1,361.25 ft² or 151.25 square yard. 1 bigha in UP can range from 5 to 20 Katha. (1 Acre = 32 Katha).

• 1 Katha = 1 Biswa
• 1 Katha = 20 Dhur
• 1 Biswa = 20 Biswansi
• 1 Dhur = 1 Biswansi

West Bengal

In West Bengal, 1 Katha is equal to 720 ft². 1 bigha is equal to 20 Katha; 1 bigha = 14,400 ft².

Nepal

In Nepal, 1 Katha is equivalent to 338.55 m² (3,645 ft²). One bigha = 20 Katha in Nepal, therefore 1 Bigha = 6,771 m² (72,882 ft²).