Land Measurement in Bihar: Bigha, Katha and Dhur by District

1 bigha in Bihar is 27,225 square feet in Patna and Arrah, the value most converters use as the default. That bigha is 20 katha of 1,361.25 sq ft each. In north Bihar the katha is bigger, so the bigha is bigger too. In Bettiah it reaches 65,340 sq ft. Always ask which district's katha a paper uses.

Units used for land in Bihar

Bihar uses bigha (बीघा), katha (कट्ठा), dhur (धुर) and dhurki in village deals. Revenue records use acre and decimal (डिसमिल, also written dismil). The decimal is the same everywhere: 435.6 sq ft, or 1/100 of an acre. It is the safest unit for comparing deeds from two districts.

The chain of units

• 1 bigha = 20 katha
• 1 katha = 20 dhur
• 1 dhur = 20 dhurki
• 1 acre = 100 decimal

This chain of 20 holds across Bihar. What changes is the size of the katha. In Patna it is 1,361.25 sq ft, so 1 dhur is 68.0625 sq ft and 1 dhurki is about 3.4031 sq ft. Dhurki is rarely used today.

District values: bigha, katha and dhur

These are commonly used values gathered from secondary sources. No official Bihar government page with district katha values was found.

For Siwan only a katha value of 1,520 sq ft was found, from a single source. The Muzaffarpur katha also rests on one source only. Values for Gaya, Bhagalpur, Purnia, Darbhanga and other districts were not found, so ask locally there.

Acre and hectare in katha, district by district

So in Patna, 1 acre is 1.6 bigha or 32 katha, and 1 hectare is about 79.07 katha. In Bettiah the same acre is only about 13.33 katha.

Official records unit and portal

Land records are on Bihar Bhumi, run by the Revenue and Land Reforms Department. In the jamabandi and khatiyan, the area (rakba) is written in acre and decimal. Katha, dhur and bigha are used in local deals and in older survey papers.

Reading a record is easy once you convert decimals. Say the rakba is 25 decimal. That is 10,890 sq ft. In Patna terms it is 8 katha. In Chhapra it is 6.25 katha, and in Bettiah about 3.33 katha. Same land, different katha count.

जमीन नापने का फार्मूला (land measurement formula)

1. Measure length and breadth in feet and multiply them to get square feet.
2. Divide by 435.6 to get decimal. This works in every district.
3. Divide by your district's katha size to get katha. In Patna that is 1,361.25.

Example: a plot of 50 ft by 40 ft is 2,000 sq ft. That is about 4.59 decimal, or about 1.47 katha by the Patna measure. For uneven plots use the land area calculator.

Common mistakes

• Using the Patna katha everywhere. A Bettiah bigha of 65,340 sq ft is 2.4 Patna bighas. Converting it with the Patna value gives a badly wrong answer.
• Mixing up katha in Bihar and West Bengal. The Bengal katha is much smaller. Check the state and district first.
• Rounding dhur too early. Some sources round the Patna dhur to 68.4 sq ft. Over a few katha the error adds up, so use 68.0625.
• Ignoring the decimal in records. The jamabandi area in decimal is the fixed number. Convert from it, not from a spoken katha count.

Sources differ for some districts, and these figures come from local practice, not a government notification. For a sale, partition or court matter, confirm the unit with the amin or the local revenue office and check the jamabandi on Bihar Bhumi. Try our katha to square feet and katha to decimal converters for quick sums.