Ask ten people in Bihar how many square feet are in a Katha and you will hear two answers: 1,361 square feet and about 1,488 square feet. Both are correct — they belong to two different Katha standards used in the state. This guide gives you the conversion table for both, the formula, and how to tell which standard your plot follows.
If your documents use Decimal instead, see our Katha to Decimal converter and our guide to how many Katha are in 1 Bigha in Bihar.
Quick answer
- Patna/Arrah revenue standard: 1 Katha = 1,361.25 sq ft (126.46 sq m). This is the figure in most government records and the one most websites quote.
- Common practical rate used across much of Bihar: 1 Katha ≈ 1,487.6 sq ft (138.2 sq m), because it follows the widely used 3.415 Decimal per Katha.
- 1 Dhur = 68.06 sq ft (at 1,361.25) or about 74.38 sq ft (at 1,487.6).
- Difference between the two standards: about 126 sq ft per Katha — small for one Katha, serious for ten.
Katha to square feet conversion table (Bihar)
| Katha | Sq ft (1,361.25 standard) | Sq ft (1,487.6 standard) |
|---|---|---|
| 1 | 1,361.25 | 1,487.6 |
| 2 | 2,722.5 | 2,975 |
| 3 | 4,083.75 | 4,463 |
| 4 | 5,445 | 5,950 |
| 5 | 6,806.25 | 7,438 |
| 10 | 13,612.5 | 14,876 |
| 15 | 20,418.75 | 22,314 |
| 20 (1 Bigha) | 27,225 | 29,751 |
The formula
Square feet = Katha × (sq ft per Katha in your standard)
Katha = Square feet ÷ (sq ft per Katha in your standard)
Worked example, both ways. A plot is advertised as 2,500 sq ft. In Katha, that is 2,500 ÷ 1,361.25 = 1.84 Katha on the revenue standard, but 2,500 ÷ 1,487.6 = 1.68 Katha on the practical rate. If you are comparing a price quoted per Katha against one quoted per square foot, using the wrong divisor quietly changes the deal by roughly 9%.
Why are there two answers?
Because the Katha is defined through Decimal in everyday practice, and Bihar uses two Decimal values for it. The revenue tradition around Patna and Arrah fixes 1 Katha at exactly 3.125 Decimal; since 1 Decimal is 435.6 sq ft, that gives 3.125 × 435.6 = 1,361.25 sq ft. The practical rate used in much of the rest of the state takes 1 Katha as 3.415 Decimal, which gives 3.415 × 435.6 ≈ 1,487.6 sq ft.
Most converter websites show only the 1,361.25 figure. That is the right answer for Patna/Arrah-standard documents — and the wrong answer for a plot being measured at the 3.415 rate. The standard is a property of your district and your documents, not a universal constant.
Katha in other states is a different size again
For comparison: in West Bengal 1 Katha is only 720 sq ft, and in Assam it is about 2,880 sq ft. A “5 Katha plot” can therefore mean 3,600 sq ft in Kolkata’s terms or 14,400 sq ft in Assam’s. If you are reading listings or documents from outside Bihar, convert from that state’s Katha, never from Bihar’s.
Frequently asked questions
How many square feet in 1 Katha in Bihar?
1,361.25 sq ft on the Patna/Arrah revenue standard, and about 1,487.6 sq ft at the common 3.415 Decimal rate used across much of the state. Check which one your documents use.
How many square feet in 1 Dhur in Bihar?
A Dhur is one-twentieth of a Katha: 68.06 sq ft on the revenue standard, about 74.38 sq ft on the practical rate.
How do I convert square feet back to Katha?
Divide the square feet by the sq ft value of one Katha in your standard. Example: 5,445 sq ft ÷ 1,361.25 = exactly 4 Katha.
Why does my plot’s Katha count change between two measurements?
It usually means the two measurements used different standards. Ask the measurer which rate — 3.125 or 3.415 Decimal per Katha — he applied, and get it written on the measurement note.
Which figure should I use when buying land?
The one in the land records for that plot and the practice of that district’s revenue office. For any transaction, confirm the applicable standard locally before money changes hands.
Bottom line
In Bihar, 1 Katha is 1,361.25 sq ft in revenue-standard terms and about 1,487.6 sq ft at the practical rate — know which standard your plot follows before you multiply anything. For Decimal-based conversions, use our Katha to Decimal converter, and see the Bigha to Katha guide for the larger units.
