Bigha to katha, katha to sq ft: West Bengal land units without the confusion

Land in Bengal is sold in katha, recorded in decimals and acres, talked about in bigha, and built on in sq ft. One plot can show up in four units across four documents. Sellers who quote in one unit and register in another are not always being careless.

Here are the conversions that matter, from bigha to katha and katha to sq ft, and how to use them to judge a land price.

Bigha to katha: the land units used in West Bengal

These are the standard West Bengal values. Keep this list on your phone when you visit land.

• 1 bigha = 20 katha = 14,400 sq ft
• 1 katha = 16 chatak = 720 sq ft (about 66.9 sq m)
• 1 chatak = 45 sq ft
• 1 decimal = 435.6 sq ft
• 1 acre = 100 decimal = 43,560 sq ft
• 1 acre = about 60.5 katha, or a little over 3 bigha

So to turn bigha into katha, multiply by 20. Half a bigha is 10 katha. A quarter bigha is 5 katha.

Katha to sq ft, and back again

This is the conversion you will use most, because builders and architects work in sq ft.

• 2 katha = 1,440 sq ft
• 3 katha = 2,160 sq ft
• 5 katha = 3,600 sq ft
• 2 katha 8 chatak = 1,440 + 360 = 1,800 sq ft

Going the other way, divide sq ft by 720. A 1,224 sq ft plot is 1.7 katha. A 1,512 sq ft plot is 2.1 katha. A 1,800 sq ft plot is exactly 2.5 katha.

Remember that sq ft of land is not sq ft of house. Building rules, setbacks and road width decide how much you can build on a plot. A 3 katha plot does not give you a 2,160 sq ft house on every floor.

Decimals and acres: what the land record uses

The government land record in West Bengal usually shows area in acres and decimals, not katha. That is why you need the decimal conversion.

• 1 decimal = 435.6 sq ft, which is about 0.6 katha
• 1 katha is about 1.65 decimal
• 3 katha is about 4.96 decimal
• 10 decimal = 4,356 sq ft, about 6 katha

If a seller says 4 katha and the record shows 5.5 decimal, the record says about 3.3 katha. The record wins. Check it on Banglarbhumi using our guide to the khatian and mouza map.

Buying from Odisha, Bihar or Assam? Your bigha is different

A bigha is not the same size across India. The West Bengal bigha is 14,400 sq ft. In parts of Bihar, Assam and Uttar Pradesh it is a different number, and Odisha land records use acres, decimals and gunth rather than bigha.

If you are in Bhubaneswar, Jamshedpur or Guwahati and looking at land near Kolkata, do not carry your home state's bigha with you. Convert everything to sq ft, then compare. The decimal is the same everywhere at 435.6 sq ft, which makes it the safest common unit.

How to read land price in Kolkata per katha

Land price in Kolkata is almost always quoted per katha. To compare it with a flat, or with a plot quoted per sq ft, divide the katha price by 720.

• ₹10 L per katha = about ₹1,390 per sq ft of land
• ₹25 L per katha = about ₹3,470 per sq ft
• ₹50 L per katha = about ₹6,940 per sq ft

Land price in Kolkata swings hugely by location. Village land on the outer edges of Hooghly and South 24 Parganas can trade below ₹10 L a katha, while plots in the old central neighbourhoods go well beyond ₹1 Cr a katha. Road width, the land classification and clear title move the price more than the neighbourhood name does.

For a real example: plots at Codename By The Garden in Shriram Grand City are listed at about ₹3,250 per sq ft. That is about ₹23.4 L per katha, with roads, drains and title already sorted inside a RERA-registered layout.

Mistakes we see with land units

• Paying on the seller's area, not the recorded area. Always pay on the smaller of the deed, the record and the survey.
• Mixing up gross and net area. In plotted layouts, roads and parks are taken out of the gross land. Ask for the net plot area.
• Rounding chatak. One chatak is 45 sq ft. On a ₹30 L a katha plot, a few chatak are several lakh rupees.

Our land buying checklist covers what to check before you pay anything.

Want the real area and price of a plot checked?

Send us the dag number, the area the seller is quoting and the asking price. We will convert it, check it against the record and tell you what you are really paying per sq ft.

See our rentals service, browse verified properties, or talk to our legal and loan help desk. We are a RERA-registered agent, WBRERA/A/HOW/2025/000651. This is general guidance and not legal advice; check the specifics for your property with a professional.