Decimal to katha depends on where your land is. In West Bengal, 1 decimal = 0.605 katha. In Patna and Arrah in Bihar, 1 decimal = 0.32 katha. The decimal (dismil, डिसमिल) is always 435.6 sq ft. The katha (कट्ठा) is not, so pick your region before you convert.
1 decimal in katha, region by region
| Region | 1 katha in sq ft | 1 decimal in katha |
|---|---|---|
| West Bengal, Jharkhand (Ranchi), Assam (Barak valley) | 720 | 0.605 |
| Bihar: Patna and Arrah | 1,361.25 | 0.32 |
| Bihar: Siwan | 1,520 | 0.2866 |
| Bihar: Chhapra; Jharkhand: Palamu | 1,742.4 | 0.25 |
| Bihar: Hajipur and Muzaffarpur | 1,901.25 | 0.2291 |
| Bihar: Bettiah (West Champaran) | 3,267 | 0.1333 |
| Assam (Brahmaputra valley) | 2,880 | 0.15125 |
| Madhya Pradesh | 600 | 0.726 |
These katha sizes are commonly used local values, not figures from a government notification. Within Bihar the katha is smallest around Patna and biggest in West Champaran. That is why two people in Bihar can give you different answers for the same plot.
Size of one katha by region
| Region | 1 katha in sq ft | In sq m | In decimal |
|---|---|---|---|
| West Bengal, Jharkhand (Ranchi), Assam (Barak valley) | 720 | 66.8902 | 1.6529 |
| Bihar: Patna and Arrah | 1,361.25 | 126.4643 | 3.125 |
| Assam (Brahmaputra valley) | 2,880 | 267.5608 | 6.6116 |
| Madhya Pradesh | 600 | 55.7418 | 1.3774 |
| Bihar: Chhapra; Jharkhand: Palamu | 1,742.4 | 161.8743 | 4 |
| Bihar: Hajipur and Muzaffarpur | 1,901.25 | 176.6319 | 4.3647 |
| Bihar: Siwan | 1,520 | 141.2126 | 3.4894 |
| Bihar: Bettiah (West Champaran) | 3,267 | 303.5142 | 7.5 |
How to convert decimal to katha
katha = decimals × 435.6 ÷ (sq ft in your katha)
Example 1, Kolkata: a 5 decimal plot is 5 × 435.6 = 2,178 sq ft. Divide by 720 and you get 3.025 katha. The part after the point can be turned into chatak, since 1 katha = 16 chatak in Bengal: 0.025 × 16 = 0.4 chatak. So the plot is about 3 katha and less than half a chatak.
Example 2, Patna: 10 decimal is 4,356 sq ft. Divide by 1,361.25 and you get 3.2 katha. In Bihar a katha has 20 dhur, so 0.2 katha × 20 = 4 dhur. The plot is 3 katha 4 dhur.
Example 3, Chhapra: here the numbers are neat. 1 katha is exactly 4 decimal, so 10 decimal is 2.5 katha, or 2 katha 10 dhur.
Example 4, Guwahati: the Brahmaputra valley katha is large, 2,880 sq ft, because the Assam bigha is split into only 5 katha. 20 decimal is 8,712 sq ft, which is 3.025 katha. A katha there has 20 lessa, so the extra 0.025 katha is half a lessa.
Decimal to katha table by region
| Decimal | Katha West Bengal, Ranchi | Katha Bihar (Patna, Arrah) | Katha Assam (Brahmaputra valley) | Katha Madhya Pradesh | Katha Chhapra, Palamu |
|---|---|---|---|---|---|
| 1 | 0.605 | 0.32 | 0.15125 | 0.726 | 0.25 |
| 2 | 1.21 | 0.64 | 0.3025 | 1.452 | 0.5 |
| 3 | 1.815 | 0.96 | 0.45375 | 2.178 | 0.75 |
| 4 | 2.42 | 1.28 | 0.605 | 2.904 | 1 |
| 5 | 3.025 | 1.6 | 0.75625 | 3.63 | 1.25 |
| 6 | 3.63 | 1.92 | 0.9075 | 4.356 | 1.5 |
| 8 | 4.84 | 2.56 | 1.21 | 5.808 | 2 |
| 10 | 6.05 | 3.2 | 1.5125 | 7.26 | 2.5 |
| 15 | 9.075 | 4.8 | 2.2687 | 10.89 | 3.75 |
| 20 | 12.1 | 6.4 | 3.025 | 14.52 | 5 |
| 25 | 15.125 | 8 | 3.7812 | 18.15 | 6.25 |
| 40 | 24.2 | 12.8 | 6.05 | 29.04 | 10 |
| 50 | 30.25 | 16 | 7.5625 | 36.3 | 12.5 |
| 100 | 60.5 | 32 | 15.125 | 72.6 | 25 |
Regional columns use the most commonly used size in each area. Confirm your local size with the revenue office.
Tips for Bihar, Jharkhand and Bengal buyers
- The record is in decimal. Khatiyan and jamabandi entries in Bihar, Jharkhand and West Bengal show area in acre and decimal. Treat the decimal figure as the base and convert to katha only to understand the local talk.
- Ask "which katha?" If a seller near Hajipur and a broker from Patna both quote katha, they may mean different sizes. Ask for the area in decimal or square feet.
- Do not round 0.605 to 0.6. On a 50 decimal plot in Bengal that makes about a quarter katha vanish.
- Verify locally. For a sale, partition or court matter, confirm the katha size with the circle office, amin or the local revenue office, and check the plot on Bihar Bhumi, Jharbhoomi or Banglarbhumi.
Questions people ask
1 decimal me kitna katha hota hai?
It depends on the katha of your area. In West Bengal and Ranchi, 1 decimal is 0.605 katha. In Patna and Arrah it is 0.32 katha, and in Chhapra it is 0.25 katha.
1 dismil in katha in Bihar?
Bihar has several katha sizes. 1 dismil is 0.32 katha in Patna and Arrah, about 0.2866 in Siwan, 0.25 in Chhapra, about 0.2291 in Hajipur and Muzaffarpur, and about 0.1333 in Bettiah. Confirm the local katha with the circle office.
5 decimal to katha in West Bengal?
5 decimal is 2,178 sq ft. With the 720 sq ft Bengal katha, that is 3.025 katha.
How many katha is 10 decimal?
10 decimal is 6.05 katha in West Bengal and 3.2 katha in Patna. In Chhapra it is 2.5 katha.
Is dismil the same as decimal?
Yes. Dismil is the local name for the decimal. It is 435.6 sq ft, one hundredth of an acre, in every state.
Local units can differ inside a state. Before a sale, partition or court filing, confirm the unit with your tehsil, circle or revenue office and check the land record. How we check our numbers.