Article — Katha to Square Feet Converter
Katha to square feet converter for India and Bangladesh
A Katha is a traditional South Asian land area unit used in eastern India, Bangladesh, and Nepal. One Katha equals roughly 720 square feet in West Bengal and Bangladesh, but 1,361.25 sq ft in Bihar, 1,742 sq ft in Jharkhand, and 2,880 sq ft in Upper Assam. To convert Katha to square feet, multiply by the regional factor that matches the property deed.
This converter handles all six common regional standards and outputs square feet, square meters, square yards, acres, hectares, and Bigha at once. It is built for property buyers, brokers, and lawyers who need quick, region-aware land-area conversions.
What is a Katha?
A Katha (Bengali: কাঠা, Hindi: कट्ठा, Assamese: কঠা) is a unit of land area still in everyday legal and commercial use across the eastern Indian subcontinent. Despite metrication efforts in the mid-20th century, Katha remains a recognised unit in government revenue records, property registrations, and real estate listings in Bihar, West Bengal, Jharkhand, Assam, Nepal, and Bangladesh.
The word "Katha" derives from a Sanskrit root meaning a piece of wood — a reference to the wooden measuring rods used in pre-modern surveys. The unit is at least a thousand years old, predating the British colonial period by centuries.
The Katha system has four nested units: Bigha > Katha > Dhur > Dhurki. The ratios are 20:20:20 — twenty Katha to a Bigha, twenty Dhur to a Katha, twenty Dhurki to a Dhur. The base-20 structure parallels the base-60 system of time and angle, both ancient base-arithmetic legacies.
Katha to square feet formula
The conversion is a single multiplication: square feet = Katha × regional factor. The factor varies because each region settled on its own square-foot equivalent during British colonial codification. The factor is not approximate — within each region it is exact and legally recognised.
For West Bengal and Bangladesh, the factor is 720. For Bihar (Patna and Arrah district standards) and Eastern Uttar Pradesh, the factor is 1,361.25. For the newer Jharkhand standard, 1,742. For Upper Assam, 2,880. Lower Assam (Cachar district) reverts to 720, like West Bengal.
Regional Katha values
The variation is significant. A 10-Katha plot in West Bengal is 7,200 sq ft — a typical urban single-family lot. The same 10-Katha plot in Bihar is 13,612 sq ft, almost double, large enough for a small apartment building. In Assam, 10 Katha would be 28,800 sq ft — more than half an acre.
Always cross-check the source of the Katha number. State government revenue records and patwari (village land-record) documents specify the local Katha standard. Real estate brokers occasionally use the West Bengal standard out of habit even in non-Bengali states; this leads to over- or under-statement of plot size by factors of 2 to 4.
Katha vs Bigha vs Dhur
The Katha sits in the middle of a hierarchy. Above it is the Bigha — usually 20 Katha, though Assam uses 5 Katha per Bigha (with a much larger Katha). Below it are the Dhur (1/20 of a Katha) and the Dhurki (1/400). The whole system is base-20, with each step a factor of twenty.
- 1 Bigha = 20 Katha (most regions); 5 Katha (Assam)
- 1 Katha = 720 to 2,880 sq ft (region-dependent)
- 1 Dhur = 1/20 Katha = 36 to 144 sq ft
- 1 Dhurki = 1/20 Dhur = 1.8 to 7.2 sq ft
- Bigha in West Bengal = 14,400 sq ft (20 × 720)
- Bigha in Assam = 14,400 sq ft (5 × 2,880) — same area, different counting
Katha and square feet in property deeds
Modern property deeds in West Bengal, Bihar, Jharkhand, and Assam typically state land area in both Katha and square feet, with sometimes a third entry in square meters. The Katha figure is the legal one — buyers transact in Katha. The square-foot figure is for construction estimates and architectural plans.
When buying or selling, always verify three numbers: Katha count, regional standard, and square-foot equivalent. A 5-Katha plot at the West Bengal standard is 3,600 sq ft. A 5-Katha plot at the Bihar standard is 6,806 sq ft. If the deed says "5 K (1,361.25 sq ft per Katha)" you know the standard; if it just says "5 K" you must establish the standard from context.
For Indian property listings on classified sites, the "sq ft per Katha" footnote or formula at the bottom of the listing reveals which standard the seller is using. If absent, ask before negotiating price per Katha.
Common Katha conversion mistakes
The biggest mistake is assuming the Katha is universal. It is not — multiplying by a fixed 720 in Bihar would understate the area by 47%. Always pick the regional factor. The second mistake is confusing Katha with Decimal, another South Asian land unit. The Decimal (or "Dec") equals 100 sq meters or 1,076 sq ft — distinct from any Katha.
A third mistake is rounding too early. Converting Katha → sq ft → sq m → acres without keeping enough decimals introduces drift. Keep at least four significant figures in intermediate values, then round at the end. The converter on this page does this automatically.
Assam Bigha = 5 Katha but each Katha is 2,880 sq ft, giving 14,400 sq ft per Bigha. West Bengal Bigha = 20 Katha but each Katha is 720 sq ft, also giving 14,400 sq ft per Bigha. Same Bigha area, totally different Katha counts. Cross-region comparisons need both numbers, not just one.
History of the Katha measurement
The Katha originated in the Pala Empire period (8th–11th century CE) in what is now Bihar, West Bengal, and Bangladesh. Originally, one Katha was the amount of land a single plowman with one plow could work in one day — a sensible agricultural definition that varied with soil and crop.
British colonial revenue administrators in the 18th and 19th centuries needed fixed values for tax calculation. They formalised regional standards: 720 sq ft in West Bengal, 1,361.25 in Bihar, 2,880 in Assam. Different regions kept their own values to preserve legal continuity. After Indian independence in 1947 and Bangladesh independence in 1971, these regional Katha values were retained in state land laws.
Quick Katha conversion FAQ
Common conversions at the West Bengal/Bangladesh standard: 1 K = 720 sq ft, 5 K = 3,600 sq ft, 10 K = 7,200 sq ft, 20 K = 14,400 sq ft (1 Bigha). At the Bihar standard: 1 K = 1,361.25 sq ft, 5 K = 6,806.25 sq ft, 10 K = 13,612.50 sq ft. The FAQ tab covers more edge cases.
For square meters, multiply the sq ft result by 0.092903. For acres, divide sq ft by 43,560. For hectares, divide sq m by 10,000. The converter does all these at once and shows the full breakdown.