JoseFitani
🗺️ Area & Perimeter

Land Measurement Calculator

Convert land areas between common units: km², m², acres, hectares, square miles and square feet.

This page explains how the land measurement calculator works, the data and formulas behind it, and how to interpret the result. The spherical excess formula gives the exact area of a polygon on a sphere. It works for polygons of any size, from small plots to entire countries, and is accurate to within ~0.1% of the more complex ellipsoidal formula. The tool is one of 329 free, open tools on JoseFitani for maps and geography. It runs in your browser with no sign-up needed. Use the search field or click the map to drop a pin - the tool uses the spherical excess formula for area on a sphere, plus great-circle distances for perimeter and returns the result in seconds. Below you'll find a step-by-step guide, real use cases, the methodology, FAQs, and data sources.

Click on the map to add vertices. The polygon will be drawn and the area calculated in real time.

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How to use this tool

1
Enter your input

Type your query, paste coordinates, or click on the map. The tool uses the spherical excess formula for area on a sphere, plus great-circle distances for perimeter to process your input locally in the browser.

2
View the result

The result appears instantly with the map showing your location. You can adjust by clicking elsewhere or searching a new place.

3
Copy or share

Click Copy to save to clipboard, or Share to send a direct link with the exact inputs.

What people use this tool for

Realty listing conversion

Indian property listings flip between square feet, square yards, and acres depending on the city and the plot size. A buyer comparing a 2,400 sq ft apartment plot with a 1.5-acre farm needs one common unit. Converting everything to square metres puts both listings on the same scale.

Example: A buyer in Hyderabad converts a 267 sq yd layout plot to square metres to compare it fairly against a listing quoted in acres.
Agricultural subsidy paperwork

Farm schemes and crop-insurance forms ask for holding size in hectares, while village records may state acres or bighas. Entering the deed figure and reading off hectares fills the form without arithmetic slips. Exact factors matter because subsidy bands have hard cut-offs.

Example: A wheat farmer in Madhya Pradesh converts 12.5 acres to hectares for a crop-insurance form that rejects any unit except hectares.
Title deed interpretation

Old deeds describe land in units the current owner may never use day to day. Converting the deed's figure into square feet or square metres makes the holding concrete. It also exposes transcription errors when the converted number looks absurd for the plot.

Example: An heir in Lucknow converts a 1940s deed stated in acres into square metres and realises the plot is half the size the family assumed.
Inheritance division planning

Splitting a family holding fairly means each sibling's share converts cleanly into the unit the local registrar uses. Running each share through the converter before the partition deed is drafted avoids rounding disputes. Exact factors keep the shares summing to the original total.

Example: Three siblings dividing a 9-acre orchard in Himachal convert each share to square metres so the partition deed lists identical totals.

How it's calculated

1 km² = 1,000,000 m² = 100 hectares = 247.105 acres ≈ 0.3861 mi².

The calculation runs in your browser - no data is sent to our servers. Map tiles come from OpenStreetMap (ODbL license), geocoding uses Nominatim (1 request/second limit), and elevation uses the Open-Elevation API backed by SRTM data. All are free, open services.

All calculations use the WGS84 datum (EPSG:4326), the same as GPS. For other datums (NAD27, NAD83, ETRS89), a separate conversion is needed. The difference is typically under 1 metre - negligible for most uses but important for survey-grade work.

The formulas match those in professional GIS software (QGIS, ArcGIS, Global Mapper), just in a browser-friendly form. For sub-metre accuracy, use professional software with ellipsoidal calculations. Results are shown in multiple units: km and miles for distance, km²/m²/hectares/acres for area, metres and feet for elevation. Conversion factors are exact (1 mile = 1.609344 km), so the only error source is input precision.

Related tools and resources

For more tools in this category, explore the related tools listed below. Each tool includes full documentation, examples and FAQs. Explore related tools in our Area category for complementary functionality. See the Tools index for all 329 tools, or read our blog for in-depth articles on geography and maps.

Frequently asked questions

How many acres in a hectare?

1 hectare = 2.47105 acres.

What is the exact conversion factor for acres to square metres?

One international acre equals exactly 4,046.8564224 square metres. The figure comes from the 1959 international yard agreement that fixed the yard at 0.9144 metres. This converter uses the full-precision factor, not a rounded 4,047.

How many square metres are in a hectare?

Exactly 10,000 square metres, by definition. A hectare is a square 100 metres on each side, which is why the metric land units convert so cleanly. One square kilometre therefore holds exactly 100 hectares.

How do square miles convert to square kilometres?

One square mile equals 2.589988110336 square kilometres, since a mile is exactly 1.609344 kilometres and squaring it gives the area factor. In imperial terms, a square mile also equals exactly 640 acres. Land registries in the US still describe large rural parcels in sections of one square mile.

Are these conversions exact or approximate?

The metric-imperial factors are exact by international definition, and this tool applies them at full precision. What you see rounded on screen is display rounding only; the underlying arithmetic keeps the full factor. For legal work, though, always confirm which definition your jurisdiction's registry uses.

Why does my result differ slightly from another converter?

Small differences usually come from rounded intermediate factors, for example using 4,047 instead of 4,046.8564224 for an acre. A second cause is the US survey foot, which differs from the international foot by about two parts per million. On large parcels those tiny gaps become visible.

What about regional units like bigha or guntha?

Regional units are deliberately excluded because their size changes by state and even by district: a bigha in Punjab is not a bigha in Bihar. Converting them needs the local definition, and a single fixed factor would mislead. Stick to the standard units here and confirm local units with the area's land records.

Can I convert between square feet and square yards?

Yes. One square yard equals exactly nine square feet, and both convert to square metres through the exact foot definition of 0.3048 metres. Indian layout plots commonly use square yards, while built-up area uses square feet, so this pair comes up constantly in property math.

Does the conversion need the internet?

No. Unit conversion is arithmetic with fixed factors, and it runs entirely in your browser. Load the page once and every conversion works with the network off.

Data sources & methodology