A friend of mine was negotiating for a plot near Tezpur last year, and the seller kept quoting the size as “2 Bigha, 3 Katha.” My friend, who grew up in Delhi and only ever dealt with square feet, had no real sense of what that meant he just nodded along and trusted the broker’s number. It was only when he asked me to double-check before signing anything that we sat down and actually converted it, and the figure the broker gave turned out to be about 1,800 sq ft short of what he’d quoted.
That gap is exactly why this calculator exists. Bigha, Katha, and Lessa aren’t going away from Assam’s land deals anytime soon, but they also don’t mean anything to a bank, a builder’s quote, or an online property listing those all run in square feet. Here’s how the conversion actually works, and a tool to do it instantly.
Bigha, Katha, and Lessa how they relate to each other
Assam’s Revenue and Disaster Management Department, and Mission Basundhara‘s land digitisation drive, both use the same traditional units for on-ground land records: Bigha at the top, Katha as a subunit of Bigha, and Lessa as the smallest unit, a subunit of Katha.
| Unit | In Katha | In Lessa | In Sq. Ft. | In Sq. M. |
|---|---|---|---|---|
| 1 Bigha | 5 Katha | 100 Lessa | 14,400 sq ft | 1,337.8 sq m |
| 1 Katha | — | 20 Lessa | 2,880 sq ft | 267.56 sq m |
| 1 Lessa | — | — | 144 sq ft | 13.38 sq m |
| 1 Acre | 15.125 Katha | 302.5 Lessa | 43,560 sq ft | 4,046.86 sq m (3.025 Bigha) |
14,400
That’s the one number worth memorising if you’re dealing with Assam land deals regularly. 1 Bigha in Assam equals 14,400 square feet — the same figure used in West Bengal, though West Bengal splits its Bigha into 20 Katha of 720 sq ft each, while Assam splits the same 14,400 sq ft into just 5 Katha of 2,880 sq ft each. Same Bigha, completely different Katha. That’s the exact confusion a broker quoting numbers loosely can create, and it’s worth checking which state’s convention someone is actually using before you assume.
How the calculation works
Since real plots are rarely round numbers, land in Assam usually gets described as a mix say, 1 Bigha, 2 Katha, 10 Lessa. The calculator adds up each part separately in square feet, then totals them.
- Bigha × 14,400 = square feet from the Bigha portion
- Katha × 2,880 = square feet from the Katha portion
- Lessa × 144 = square feet from the Lessa portion
- Add all three for the total, then divide by 10.7639 for square meters, or 43,560 for acres
Worked example 1 Bigha, 2 Katha, 10 Lessa
Bigha: 1 × 14,400 = 14,400 sq ft
Katha: 2 × 2,880 = 5,760 sq ft
Lessa: 10 × 144 = 1,440 sq ft
Total: 14,400 + 5,760 + 1,440 = 21,600 sq ft
In square meters: 21,600 ÷ 10.7639 ≈ 2,006.71 sq m
In acres: 21,600 ÷ 43,560 ≈ 0.496 acres
That’s roughly the size discrepancy my friend nearly missed near Tezpur the difference between “2 Bigha, 3 Katha” as quoted and what the land actually measured out to was close to this same order of magnitude, once we did the sq ft math properly.
How to Use the Calculator
Step 1. Enter the Bigha value from your land document.
Step 2. Enter the Katha value (0 to 4).
Step 3. Enter the Lessa value (0 to 19).
Step 4. Click “Convert Assam Land Area” to see your total in Square Feet, Square Meters, and Acres instantly.
Some things people ask us often
How many square feet are in 1 Bigha of land in Assam?
1 Bigha in Assam is exactly 14,400 square feet, or 1,337.8 square meters.
How many Katha make 1 Bigha in Assam?
1 Bigha contains exactly 5 Katha in Assam.
How many Lessa make 1 Katha in Assam?
1 Katha contains exactly 20 Lessa, and 1 Lessa equals 144 sq ft.
Is Bigha measurement in Assam different from West Bengal or Bihar?
The Bigha itself isn’t different in size between Assam and West Bengal both are 14,400 sq ft. What differs is how it’s divided: Assam splits it into 5 Katha, West Bengal into 20 Katha, so a Katha means a very different area depending on which state’s deed you’re reading. Bihar’s Bigha is a separate size altogether, at 27,220 sq ft.
My land document mixes units it says “1 Bigha 3 Katha” in one place and “18,240 sq ft” in another. Should these match exactly, or is some rounding normal?
They should work out to the same figure if both are using Assam’s standard conversion. 1 Bigha 3 Katha = 14,400 + (3 × 2,880) = 22,640 sq ft, not 18,240 so if your document shows a mismatch like that, it’s worth flagging with the surveyor or Mondal before you rely on either number, rather than assuming it’s just rounding.
Is this an official government conversion tool?
No. The conversion factors used here match Assam Revenue Department standards and Mission Basundhara’s records, but this calculator is an independent tool for quick reference. For anything going into a registered deed or land record, the figures on your actual Jamabandi or Patta, verified by a Mondal or the Revenue Circle office, are what legally count.
Official Resources
For anything involving an actual land transaction or record correction, these are the official channels to check:
If you’re mid-negotiation on a plot and the numbers being quoted don’t add up the way you expect, that’s worth resolving before any advance changes hands, not after.
