Katha to Decimal Converter (Kattha to Dismil)

1 katha to decimal is 1.6529 decimal in West Bengal and Ranchi, and 3.125 decimal in Patna and Arrah. It is 4 decimal in Chhapra. The answer changes because the katha (कट्ठा, kattha) is a local unit, while the decimal (dismil) is always 435.6 sq ft.

Step 1: find your katha

Choose the line for the place where the land is, not where you live.

• West Bengal, Jharkhand (Ranchi), Assam (Barak valley): 1 katha = 720 sq ft = 1.6529 decimal
• Bihar, Patna and Arrah: 1 katha = 1,361.25 sq ft = 3.125 decimal
• Bihar, Siwan: 1 katha = 1,520 sq ft = 3.4894 decimal
• Bihar, Chhapra; Jharkhand, Palamu: 1 katha = 1,742.4 sq ft = 4 decimal
• Bihar, Hajipur and Muzaffarpur: 1 katha = 1,901.25 sq ft = 4.3647 decimal
• Bihar, Bettiah (West Champaran): 1 katha = 3,267 sq ft = 7.5 decimal
• Assam (Brahmaputra valley): 1 katha = 2,880 sq ft = 6.6116 decimal
• Madhya Pradesh: 1 katha = 600 sq ft = 1.3774 decimal

All of these are commonly used local values. No single government table covers them all, so check yours locally.

Size of one katha by region

Step 2: multiply

decimal = katha × (decimals in one local katha)

Or work through square feet: katha × sq ft per katha ÷ 435.6.

Step 3: add the small units

Deeds rarely say "2.5 katha". They say katha plus a smaller unit, and that unit differs by state.

Bengal: katha and chatak

A Bengal katha has 16 chatak of 45 sq ft each. One chatak is about 0.1033 decimal.

Example: "1 katha 4 chatak" in Kolkata. 4 chatak is a quarter katha, so the plot is 1.25 katha. 1.25 × 1.6529 = about 2.0661 decimal. For 1.5 katha (1 katha 8 chatak), the answer is about 2.4793 decimal.

Bihar: katha and dhur

A Bihar katha has 20 dhur. Around Patna, 1 dhur = 68.0625 sq ft, which is 0.15625 decimal.

Example: "2 katha 10 dhur" in Patna. 10 dhur is half a katha, so this is 2.5 katha. 2.5 × 3.125 = 7.8125 decimal.

Example from Hajipur: 3.5 katha × 4.3647 = about 15.2763 decimal. The same 3.5 katha in Patna would be only about 10.94 decimal. That gap is why the place matters.

Katha to decimal table by region

Regional columns use the most commonly used size in each area. Confirm your local size with the revenue office.

Why decimal is the safer unit

Khatiyan and jamabandi records in Bihar and Jharkhand, and the record of rights in West Bengal, show area in acre and decimal. Since the decimal never changes, it is the best unit for comparing a deed from one district with another. When a buyer, seller and broker each think of a different katha, settle the deal in decimal or square feet.

Tips

• Write down the katha size you used next to your answer, for example "Patna katha, 1,361.25 sq ft".
• Check the area on Bihar Bhumi, Jharbhoomi or Banglarbhumi before paying.
• For a sale, partition or court case, confirm the local katha with the circle office, amin or local land revenue office.