Standard Land Measurement Method in Bangladesh

Bangladesh measures land in two systems that sit side by side. The survey system counts in acre and decimal (satak or shotangsho), and the traditional system counts in bigha, katha and chotak. Both are standardised, they convert exactly into each other, and every khatian, deed and mouza map uses one or the other. This page explains both, the imperial and metric units behind them, and how surveyors measure a plot with Gunter's chain.

The two systems

In the decimal system one acre is split into 100 parts, and each part is one decimal (also called one percent, one satak or one shotangsho). The khatian records land as a fraction of an acre, so 0.3300 acre means 33 decimal.

In the katha system 20 katha make one bigha, and just over three bigha make one acre. Katha and bigha are what people use in conversation and in many deeds. The link between the two systems is that 1 acre = 100 decimal = 3.025 bigha = 60.5 katha.

Officially, hectares also appear on some government papers, because they are the international unit: 1 hectare = 2.471 acre = 247.1 decimal.

Inch, foot and gaj

12 inches = 1 foot, and 3 feet = 1 gaj (yard). Areas come from multiplying two lengths, so a square gaj (barga gaj) is 9 square feet (barga foot). If the length times the width of a plot comes to 4,840 square gaj, the plot is exactly one acre: for example 220 gaj by 22 gaj.

Acre, bigha, decimal, katha and chotak in square gaj and square feet

Unit	Square gaj (sq yd)	Square feet
1 acre	4,840	43,560
1 bigha	1,600	14,400
1 decimal (satak)	48.4	435.6
1 katha	80	720
1 chotak	5	45

One chotak is also 20 square hat, because a hat is 18 inches and a square hat is 2.25 square feet.

Katha, bigha and acre

• 1 katha = 16 chotak = 720 sq ft
• 1 katha = 1.653 decimal = 165.3 ojutangsho
• 1 bigha = 20 katha = 14,400 sq ft = 33.06 decimal (deeds round to 33)
• 1 shotangsho = 100 ojutangsho; 100 shotangsho = 1,000 sohosrangsho = 10,000 ojutangsho = 1 acre
• 1 acre = 3.025 bigha = 60.5 katha

On a khatian the acre figure has four decimal places, and the last two digits read as ojutangsho: 0.0825 acre is 8 decimal 25 ojutangsho. Converters: katha to sq ft, bigha to sq ft, katha to decimal.

Metric equivalents

• 1 inch = 2.54 cm; 1 metre = 39.37 inches = 3.28 feet = 1.094 gaj
• 1 kilometre = 1,094 gaj; 1 mile = 1,760 gaj = 1.609 km
• 1 square metre = 10.764 square feet; 1 hectare = 10,000 sq m = 2.471 acre

Gunter's chain (chain jarip)

Traditional survey in Bangladesh uses Gunter's chain, a steel chain 66 feet (20.12 metres) long, introduced by the English surveyor Edmund Gunter in the 1600s. It was designed so that acres come out as whole numbers: a strip 10 chains long and 1 chain wide is exactly one acre.

• 1 chain = 66 ft = 100 links; 1 link = 7.92 inches
• 1 square chain = 4,356 sq ft = 10 decimal; 10 square chains = 1 acre
• 1,000 square links = 1 decimal; 100,000 square links = 1 acre
• 80 chains = 1 mile (1,760 gaj)

Brass markers (nos or phuli) on the chain sit at every 10 links, that is every 79.2 inches, so a surveyor can read 10, 20, 30, 40 and 50 links at a glance from either end.

A measuring tape (fita) is used alongside the chain. Amins and surveyors take long boundaries with the chain and short distances or awkward corners with the tape. For a large field the chain is faster; for a small plot the tape is more convenient.

Regional units

Chattogram and Sylhet use kani, gonda, kora, kranti and til (1 kani = 20 gonda = 17,280 sq ft = 39.67 decimal). Northern districts sometimes quote a bigha of 33 decimal exactly. Neighbouring Indian states use their own bigha, from 8,712 sq ft in Himachal Pradesh to 27,000 sq ft in Uttar Pradesh. The formula page lists all the Bangladesh units, and the bigha to acre converter has a region picker for India and Nepal.

Frequently asked questions

Which unit is the official one in Bangladesh?

The acre and its hundredth, the decimal (shotangsho), as recorded on the khatian. Bigha and katha are traditional units used in deeds and everyday talk, and hectares appear on some government documents.

How many decimal in 1 bigha?

33.06 decimal exactly (14,400 ÷ 435.6). Most deeds write 33 decimal.

How many katha in 1 acre?

60.5 katha, which is 3 bigha and 0.5 katha. The saying "3 bigha = 1 acre" is short by half a katha.

Why is Gunter's chain 66 feet?

Because 10 square chains make an acre and 80 chains make a mile, so both areas and distances come out in round numbers. The 100 links also make decimal fractions easy: 1,000 square links are one decimal.

How do I convert square feet to decimal?

Divide by 435.6. The decimal to square feet converter works in both directions.