How to convert bigha, guntha, gaj and decimal to acre (state by state)

A sale deed from Bihar says 10 bigha. A plot ad in Delhi says 200 gaj. A Maharashtra 7/12 extract says 5 guntha. A broker in Chennai says 2 grounds. You want all of it in acres or square feet so you can compare prices, and every website seems to give a slightly different answer.

Most of these units are fixed. One of them, the bigha, is not, and that is where the wrong answers come from. Below are the exact figures, the bigha by state, and worked answers to the questions people search most.

The fixed units first

Start with the acre. The US National Institute of Standards and Technology (NIST SP 811, Appendix B) gives 1 acre as 43,560 square feet, and the international foot as exactly 0.3048 metre since 1959. So 1 acre is exactly 4,046.8564224 square metres. Every unit in this table is tied to the acre or the foot, so these figures do not change from state to state.

Gaj in plot ads means a square yard: 9 square feet. The Tamil Nadu survey conversion table lists the kejam (gaj) as 3 feet, 0.9144 metre, the same yard NIST uses. A "200 gaj plot" is therefore 1,800 square feet, or 167.225472 square metres.

Cent and decimal are the same area under two names: one hundredth of an acre, 435.6 square feet. The Tamil Nadu table uses cent. The Bihar revenue glossary uses decimal (dismil) and gives the same 435.6 square feet.

Ground is 2,400 square feet on the Tamil Nadu table. The same table also says 1 ground = 5.5 cent, which is 2,395.8 square feet. The two lines differ by 4.2 square feet; we use 2,400.

Guntha: 1,089 sq ft or 100 sq m?

The Poona District Gazetteer (Department of Land Records) describes the guntha as 121 square yards (a square 11 yards a side), with 40 gunthas to the acre. That is 1,089 square feet, or 101.17 square metres.

The Maharashtra Bhumi Abhilekh glossary prints both: 1 guntha = 100 square metres, or 1,089 square feet. Those are not the same. The 100 square metre figure is about 1.2 percent smaller. On one acre of 40 guntha, it would give 4,000 square metres instead of 4,046.86. Our converter uses 1,089 square feet, because that is the one that makes 40 guntha equal exactly one acre, and the glossary's own acre line says 40 guntha = 43,560 square feet.

Why a bigha has no single size

The Maharashtra land records glossary says it plainly: the bigha varies locally from about one third of an acre to one acre. The Bihar revenue glossary (approved 13 Oct 2025) says a bigha is about 20 katha, and that the katha is about 1,361 square feet around Patna but varies from region to region in Bihar.

So "10 bigha to decimal" has no single answer until you know which bigha. Here is the same 10 bigha under each size our converter carries:

The largest answer is four times the smallest. That is why a converter that only says "1 bigha = 0.625 acre" is wrong for most of the country. For a document that names a state, pick that state's bigha. For anything that matters, such as a purchase, a loan or a partition, ask the local revenue office which bigha the record uses, or use the hectares, acres or square metres if the record prints them.

Answers to the questions people actually search

• 10 bigha to decimal: 625 decimal for the Patna or eastern UP bigha, 330.578512 for the Bengal or Assam bigha. See the table above for the others.
• 1000 gaj in guntha: 1,000 square yards is 9,000 square feet, which is 8.264463 guntha (1,000 divided by 121). That is 0.206612 acre, or exactly 836.12736 square metres.
• Guntha to acre: multiply by 0.025, or divide by 40. So 5 guntha is 0.125 acre and 20 guntha is half an acre.
• Acre to bigha: 1.6 bigha (UP east), 2 (Punjab), 2.5 (Rajasthan kachha), 3.025 (Bengal or Assam), 6.4 (UP west).
• Hectare to acre: 2.471054 acre. One hectare is also 98.842153 guntha at 1,089 square feet.

How to do it in the converter

1. Open Unit Converter. It opens on Area, where the Indian land units are.
2. Type the number in Amount, for example 10.
3. Pick the From unit and To unit. Bighas are listed by region, such as Bigha (Bihar, Patna) or Bigha (West Bengal). Gaj is listed as Square yard (gaj). Or tap a chip such as Guntha to Sq ft.
4. Press Convert. The big line is the answer. It says whether the figure is exact or rounded to 6 places, and a note under it names the definition used for any state unit.
5. Look under Same amount in other units to see the area in acres, hectares, square feet and guntha at once, then use Copy summary or Download CSV to keep it with your papers.

Three checks before you trust a figure

• Which bigha, katha or marla? If the document does not name a region, do not guess. The same word can mean four times the area.
• Rounded or exact? A site that rounds 1 sq m to 10.76 sq ft is off by about 0.04 percent. On a 10 acre farm that is around 160 square feet. Our converter keeps exact fractions and only rounds what it shows.
• What does the record itself say? If the record also prints the area in hectares, acres or square metres, those are fixed units. Convert from them rather than from a customary unit.

Is what I type sent anywhere?

No. The conversion is plain arithmetic in your browser tab. We watched the network while making the screenshot above: after the page loaded, the only requests were two Google Analytics events saying the converter was opened and that something was typed. They did not include the amount, the units or the result.

FAQ

How many decimal are in 1 bigha?

It depends on the bigha. The Patna or eastern UP bigha of 27,225 square feet is 62.5 decimal. The Bengal or Assam bigha of 14,400 square feet is 33.057851 decimal. Pick the regional bigha in the Unit Converter to see yours.

How many guntha make one acre?

Forty. One guntha is 121 square yards, which is 1,089 square feet, so 40 guntha is exactly 43,560 square feet, one acre.

Is gaj the same as square yard?

Yes, in plot sizes gaj means a square yard of 9 square feet. As a length, a gaj is a yard of 3 feet, 0.9144 metre.

Are cent and decimal the same?

Yes. Both are one hundredth of an acre, 435.6 square feet. Cent is the southern name, decimal is used in Bihar and Bengal.

Which figure should I use for a property deal?

The one in the registered record. A converter gives arithmetic, not a survey. If the record uses a customary unit without saying which size, ask the local revenue or land records office.

Sources

• NIST Guide to the SI, Appendix B (section B.6: acre 43,560 square feet; yard 0.9144 metre since 1959)
• Maharashtra Bhumi Abhilekh, Resources glossary (acre, guntha, bigha)
• Poona District Gazetteer, Department of Land Records (guntha of 121 square yards)/Department%20of%20Land%20Records.htm)
• Tamil Nadu Commissionerate of Survey and Settlement, conversion table (cent, ground, kejam)
• Bihar revenue glossary, approved 13 Oct 2025 (kattha, bigha, dismil) (PDF)
• Bigha, Wikipedia (regional sizes for UP, Rajasthan, Assam and Bengal) and Measurement of land in Punjab, Wikipedia

Sources checked 21 Oct 2026. Every converted figure in this post comes from running our converter's code on that date. Regional bigha sizes outside Bihar and Maharashtra are customary published figures, not one national standard.

Written by the TaskNinja team with help from an AI writing tool, then checked against the NIST, Maharashtra, Tamil Nadu and Bihar sources above and the tool itself.