Free agricultural tool
Land Area Calculator for Agricultural Land
Measure farm land, plots and fields — then convert between acres, hectares, square feet and verified regional units. Use your result directly in the fertilizer dose calculator.
How it works
Land area formulas
| Land area formulas | Formula | Example |
|---|---|---|
| Rectangle | Area = length × width | 100 m × 50 m = 5,000 m² |
| Square | Area = side² | 25 m × 25 m = 625 m² |
| Triangle | Area = ½ × base × height | ½ × 40 m × 30 m = 600 m² |
| Trapezoid | Area = ((side A + side B) / 2) × height | ((60 m + 40 m) / 2) × 30 m = 1,500 m² |
| Four sides + diagonal | Split into two triangles along the diagonal; solve each with Heron's formula and add | Exact — no approximation |
How to calculate land area in square feet
If your dimensions are in feet, multiply: area in square feet = length in feet × width in feet. Example: 100 ft × 50 ft = 5,000 sq ft. Divide by 43,560 for acres, or by 9 for square yards. For irregular plots, divide the land into rectangles and triangles, calculate each, and add them — or measure a diagonal and use the 4-side mode above.
Why four sides alone are not enough
A quadrilateral can flex: the same four side lengths can enclose different areas depending on the angles. That is why no honest calculator gives an 'exact' area from sides alone. Measure one diagonal (corner to opposite corner) and the plot becomes two triangles — each with an exact area. Without a diagonal, only a labeled approximation is possible.
How to measure irregular land
Walk the field and divide it into simple shapes — rectangles, triangles, trapezoids. Measure each, calculate separately, and add the areas. The Irregular mode above does exactly this: add a section per part of your field and it totals them for you.
Land area conversion table
Exact definitions. Regional units appear only where verified.
| Unit | Equals | Standard |
|---|---|---|
| Square meter (m²) | 1 m² | Exact definition |
| Square kilometer (km²) | 1,000,000 m² | Exact definition |
| Square foot (ft²) | 0.09 m² | Exact definition |
| Square yard (yd²) | 0.84 m² | Exact definition |
| Acre (ac) | 4,047 m² | Exact definition |
| Hectare (ha) | 10,000 m² | Exact definition |
| Marla (marla) | 25.29 m² | Punjab revenue standard (1 marla = 272.25 sq ft) |
| Kanal (kanal) | 505.9 m² | Punjab revenue standard (1 kanal = 20 marla = 5,445 sq ft) |
| Bigha (UP) (bigha) | 2,529 m² | UP revenue (pucca) standard — 3025 sq yd (60×60 Ilahi guz); 1 bigha = 20 biswa |
| Biswa (UP) (biswa) | 126.5 m² | 1/20 bigha = 151.25 sq yd = 1361.25 sq ft |
| Biswansi (UP) (biswansi) | 6.32 m² | 1/20 biswa = 68.0625 sq ft |
| Bigha (Bihar) (bigha) | 2,529 m² | Patna survey standard — 3025 sq yd; 1 bigha = 20 katha |
| Katha (Bihar) (katha) | 126.5 m² | 1/20 bigha = 1361.25 sq ft; 1 katha = 20 dhur |
| Dhur (Bihar) (dhur) | 6.32 m² | 1/20 katha = 68.0625 sq ft; 1 dhur = 20 dhurki |
| Dhurki (Bihar) (dhurki) | 0.32 m² | 1/20 dhur = 3.403125 sq ft |
| Bigha (WB) (bigha) | 1,338 m² | Colonial Bengal standard — 1600 sq yd = 14,400 sq ft; 1 bigha = 20 katha = 33 decimal |
| Katha (WB) (katha) | 66.89 m² | 1/20 bigha = 720 sq ft; 1 katha = 16 chhatak |
| Chhatak (WB) (chhatak) | 4.18 m² | 1/16 katha = 45 sq ft |
| Decimal (WB) (decimal) | 40.47 m² | 1/100 acre = 435.6 sq ft (also used in Bihar) |
| Kanal (Haryana) (kanal) | 505.9 m² | Post-settlement standard — 605 sq yd = 5,445 sq ft; 1 kanal = 20 marla; 8 kanal = 1 acre |
| Marla (Haryana) (marla) | 25.29 m² | 1/20 kanal = 272.25 sq ft = 9 sarsahi |
| Sarsahi (Haryana) (sarsahi) | 2.81 m² | 1 karam² (66-inch karam) = 30.25 sq ft; 9 sarsahi = 1 marla |
| Bigha (Rajasthan, pucca) (bigha) | 2,529 m² | Shahjahani jarib (165 ft)² = 27,225 sq ft; 1 bigha = 20 biswansi |
| Bigha (Rajasthan, kachha) (bigha) | 1,619 m² | Gantari jarib (132 ft)² = 17,424 sq ft |
| Biswansi (Rajasthan) (biswansi) | 126.5 m² | 1/20 bigha = 1361.25 sq ft |
| Bigha (bigha) | 1,338 m² | General standard — 20 katha = 1600 sq yd = 14,400 sq ft = 33 decimal (district variants exist) |
| Katha (katha) | 66.89 m² | 1/20 bigha = 720 sq ft = 1.65 decimal |
| Chhatak (chhatak) | 4.18 m² | 1/16 katha = 45 sq ft (Bengal system) |
| Decimal (shotangsho) (decimal) | 40.47 m² | 1/100 acre = 435.6 sq ft |
| Alqueire paulista (alq.) | 24,200 m² | Alqueire paulista = 24,200 m² |
| Alqueire mineiro (alq.) | 48,400 m² | Alqueire mineiro/goiano = 48,400 m² |
| Alqueire baiano (alq.) | 96,800 m² | Alqueire baiano = 96,800 m² |
| Alqueire do norte (alq.) | 27,225 m² | Alqueire do norte = 27,225 m² (dictionary value preferred) |
| Dönüm (dönüm) | 1,000 m² | Legal dönüm = 1,000 m² = 1 dekar = 10 ar (NOT the old Ottoman dönüm of 918.393 m²) |
| Tsubo (坪) (坪) | 3.31 m² | Exact 400/121 m²; restricted-use unit — permitted for land/building transactions only |
| Pyeong (평) (평) | 3.31 m² | Exact 400/121 m²; commercial use banned since 1 July 2007 (informal use continues) |
| Sotka (сотка) (сотка) | 100 m² | Colloquial name for the metric are (100 m²); not a separate standard |
Sources & methodology
Universal units use exact SI and imperial definitions (1 acre = 4,046.8564224 m²; 1 hectare = 10,000 m²). Kanal and Marla use the Punjab revenue standard: 1 karam = 5.5 ft, 1 marla = 9 sq karam = 272.25 sq ft, 1 kanal = 20 marla = 5,445 sq ft. All calculations run in square meters internally and convert once to the display unit — no chained rounding.
FAQs
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