Land Area Units in India: Conversion Guide

India’s Legal Metrology Act, 2009 bases units of measure on the metric system. Land records and market conversations can still contain acres and regional names, while the Department of Land Resources expressly notes that land administration and nomenclature are diverse across states.

The safe rule is simple: standardized units can be converted mathematically; a regional unit must first be defined by the parcel’s authoritative context.

Exact baseline conversions

The SI unit of area is the square metre. NIST’s area guide confirms the decimal relationships for square metres, ares and hectares. Its conversion-factor guidance gives the acre relationship.

From these relationships:

• square metres = square feet × 0.09290304;
• square feet = square metres ÷ 0.09290304;
• hectares = square metres ÷ 10,000; and
• acres = square feet ÷ 43,560.

Keep the unrounded result in the parcel record. Round only for display, and state the rounding used.

Why regional names need a source

Names such as bigha, katha, biswa, ground, guntha, kanal and marla can depend on state, district, settlement history or document convention. A web table that assigns one value per state can still be wrong for a specific record.

Before converting a regional unit, capture:

1. the original number and spelling;
2. state, district, village and record type;
3. the document date;
4. any metric or acre equivalent printed on the same record;
5. the authority or survey office that confirms the relationship; and
6. whether the value is a legal-record convention, layout convention or informal market usage.

If the source record provides both the local unit and metric extent, use that parcel-specific relationship and flag any inconsistent documents. Do not select whichever conversion produces the expected price.

A reproducible conversion workflow

1. Preserve the original

Store “3 bigha” as an original input, not merely the converted number. This keeps the ambiguity visible until it is resolved.

2. Normalize to a standard unit

Choose square metres for statutory and survey comparison or another documented internal standard. Store the conversion factor and source with the output.

3. Reconcile all parcel records

Compare the normalized extent across the conveyance, revenue extract, survey record, encumbrance search, approved layout and physical survey. A numerical match does not prove that the boundary is the same; compare parcel geometry and subdivisions too.

4. Separate area from price

Calculate price per standardized unit only after the area source is settled. Keep asking price, guideline value and registered comparable evidence as separate fields; none is automatically the parcel’s market value.

5. Log variances

Record the documents compared, conversion factors, absolute difference, percentage difference, possible reason, responsible professional and resolution. Do not silently average conflicting extents.

The land area converter can perform arithmetic once the correct unit definition is known. The user remains responsible for selecting the definition supported by the parcel evidence.

What this guide does not prove

It does not publish a national conversion for every regional name, certify a parcel’s extent, determine a price, or reconcile a boundary. Those conclusions require the original records and, where needed, confirmation from the competent revenue or survey authority and a qualified surveyor.