Decimal, Katha, Bigha, Acre: Bangladesh Land Units Explained
A decimal is 435.6 square feet and a katha is 720 — but "one bigha" changes meaning when you cross a district line. Most land disputes about quantity start with exactly that mismatch.
Bangladesh runs two systems of land measurement side by side. Official records — khatian, dakhila, deeds — state area in acres and decimals. The market speaks in katha, bigha and chatak. If you cannot convert between them, two parties can read the same plot as two different sizes, and that is where disputes begin.
The base units
Everything reduces to square feet. Memorise these and you can derive the rest.
| Unit | Square feet | In decimals | Note |
|---|---|---|---|
| 1 chatak | 45 | 0.103 | One sixteenth of a katha |
| 1 katha | 720 | 1.653 | The Dhaka standard, used in most cities |
| 1 decimal (shatak) | 435.6 | 1 | The unit of the official record |
| 1 bigha | 14,400 | 33.06 | 20 katha — but regionally variable |
| 1 acre | 43,560 | 100 | The unit most khatians are written in |
| 1 hectare | 107,639 | 247.1 | Statistics and agriculture |
The conversions you actually use
- 1 acre = 100 decimals ≈ 3 bigha 5 katha = 43,560 sq ft
- 1 bigha = 20 katha ≈ 33 decimals = 14,400 sq ft
- 1 katha = 16 chatak = 1.653 decimals = 720 sq ft
- 1 decimal = 0.605 katha = 435.6 sq ft ≈ 40.47 sq m
- 10 decimals = 6.05 katha = 4,356 sq ft
- A katha is roughly a 20 ft × 36 ft plot
Why a bigha is not the same everywhere
The bigha is customary, not statutory. In and around Dhaka, 1 bigha = 20 katha = 33 decimals. In parts of the country — notably the north and some border districts — the customary bigha is a different size, sometimes 50 decimals, sometimes more or less. The katha varies too: it is not always exactly 720 square feet.
Reading the numbers on a khatian
A khatian normally states area as a decimal fraction of an acre, for example 0.1350 acre. Multiply by 100 for decimals: 0.1350 × 100 = 13.50 decimals. Divide by 1.653 for katha: 13.50 ÷ 1.653 ≈ 8.17 katha.
Where land spans several dags, each dag carries its own area and the khatian total is their sum. To find one co-owner’s entitlement, multiply the total by the share ("angsha") recorded against that owner — 1/4, 0.125 and so on.
Worked example
Say a khatian records 0.4800 acre and your share is one third. Total = 48 decimals; your entitlement = 48 ÷ 3 = 16 decimals = 16 × 435.6 = 6,969.6 sq ft ≈ 9.68 katha.
When the measured area disagrees with the record
A gap between what you measure on the ground and what the khatian says is extremely common. The usual reasons:
- Old surveys were run with chain and compass; some divergence from GPS measurement is normal.
- Possession boundaries drift from record boundaries over decades as ails (field ridges) move.
- A road, canal or acquisition took part of the plot and the record was never updated.
- On sloping ground, map area is the horizontal projection, not the surface area of the slope.
- Co-owners divided the land informally and never recorded it.
For a material difference, the remedy is a physical survey by a licensed amin or surveyor working from the mouza map. Drawing on a map is excellent for a first estimate and for negotiation, but a boundary dispute needs a ground survey to carry legal weight.
Frequently asked
How many square feet is one decimal?
435.6 square feet — one hundredth of an acre (43,560 sq ft).
How many decimals is one katha?
At 720 sq ft, 1 katha = 720 ÷ 435.6 = 1.653 decimals.
How many bighas in an acre?
At the Dhaka standard, 100 ÷ 33.06 = 3.025 bigha, or roughly 3 bigha and half a katha.
What is wrong with writing bighas into a contract?
The bigha varies regionally, so its meaning can be disputed later. Decimals or square feet remove the ambiguity and reconcile directly with the khatian.
Where is the hectare used?
Agricultural statistics, project documents and international reporting. 1 hectare = 2.471 acres = 247.1 decimals.
Trace a boundary on satellite imagery and read the area instantly in decimals, katha, bigha and square feet.
Measure land on the map