📐 Area Converter — 14 Units
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Area Conversion
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All 14 Units Simultaneously
⚠️ Disclaimer: All standard conversions (m², ft², acre, hectare, etc.) use exact NIST factors. Regional units (marla, kanal, bigha) use the most widely accepted Pakistan Board of Revenue and Indian standard definitions, which may vary slightly by local practice. Always verify with official local land records for legal purposes.
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Sources & Methodology
All metric and imperial conversion factors are exact per NIST SP 811 (Guide for the Use of the International System of Units, 2008). The acre definition uses the international acre (4,046.8564224 m²) per the 1959 International Yard and Pound Agreement. Regional South Asian units use Pakistan Board of Revenue and standard Indian definitions.
NIST SP 811 — Guide for the Use of the International System of Units
The authoritative US source for exact conversion factors. Key exact factors: 1 foot = 0.3048 m (exact), so 1 ft² = 0.09290304 m² (exact). 1 international acre = 4,046.8564224 m² (exact). 1 international mile = 1,609.344 m (exact), so 1 mi² = 2,589,988.110336 m² (exact).
Pakistan Board of Revenue — Official Land Measurement Standards
Official Pakistan land measurement: 1 marla = 225 sq ft; 1 kanal = 20 marla = 4,500 sq ft = 418.064 m²; 8 kanal = 1 acre. These are the legally recognised definitions for land registration throughout Pakistan and are consistent with Punjab, KPK, and Sindh revenue records.
India State Revenue Boards — Bigha Definition
Bigha definitions vary by Indian state. The pucca bigha (used in UP, Bihar, West Bengal, Rajasthan) = 3,025 square yards = 27,225 sq ft = 2,529.285 m² = 0.625 acres. This is the standard definition used in this calculator. Local definitions may differ; confirm with the relevant state revenue authority for legal purposes.
Exact Conversion Factors (all from NIST SP 811):
Base unit: square metre (m²) — all other units convert through m² 1 ft² = 0.09290304 m² (exact) • 1 m² = 10.76391042 ft² 1 acre = 4,046.8564224 m² (exact) • 1 hectare = 10,000 m² (exact) 1 mi² = 2,589,988.110336 m² (exact) • 1 mi² = 640 acres (exact) 1 marla = 225 ft² = 20.9032... m² • 1 kanal = 418.064... m² 1 bigha (pucca) = 27,225 ft² = 2,529.285... m² = 0.625 acres The common mistake in area conversion: if 1 ft = 0.3048 m, then 1 ft² = 0.3048² = 0.09290304 m² (NOT 0.3048 m²). Always square the linear conversion factor.
Base unit: square metre (m²) — all other units convert through m² 1 ft² = 0.09290304 m² (exact) • 1 m² = 10.76391042 ft² 1 acre = 4,046.8564224 m² (exact) • 1 hectare = 10,000 m² (exact) 1 mi² = 2,589,988.110336 m² (exact) • 1 mi² = 640 acres (exact) 1 marla = 225 ft² = 20.9032... m² • 1 kanal = 418.064... m² 1 bigha (pucca) = 27,225 ft² = 2,529.285... m² = 0.625 acres The common mistake in area conversion: if 1 ft = 0.3048 m, then 1 ft² = 0.3048² = 0.09290304 m² (NOT 0.3048 m²). Always square the linear conversion factor.
Last reviewed: April 2026
Area Conversion Guide — All Units Explained
Area measurement systems vary widely across countries and industries. Home sizes are measured in square feet (US, Canada, South Asia) or square metres (Europe, Australia, most of the world). Land is measured in acres (US, UK, Commonwealth), hectares (global metric standard), or regional units like marla and kanal (Pakistan, parts of India). Understanding how to convert between these systems is essential for real estate, construction, agriculture, and international comparisons.
The Critical Squaring Rule — Most Common Mistake
The most frequent error in area conversion is forgetting to square the linear conversion factor. If 1 foot = 0.3048 metres, then 1 square foot = 0.3048² = 0.09290304 square metres, NOT 0.3048 square metres. Doubling a square’s side quadruples its area. Always use the squared factor for area — this is why small measurement errors in length create proportionally larger area errors.
Area Conversion Principle
Linear: 1 ft = 0.3048 m Area: 1 ft² = 0.3048 × 0.3048 = 0.09290304 m²
Linear: 1 mile = 1,609.344 m Area: 1 mi² = 1,609.344² = 2,589,988.110336 m²
Linear: 1 km = 1,000 m Area: 1 km² = 1,000² = 1,000,000 m²
Linear: 1 mile = 1,609.344 m Area: 1 mi² = 1,609.344² = 2,589,988.110336 m²
Linear: 1 km = 1,000 m Area: 1 km² = 1,000² = 1,000,000 m²
Area Conversion Reference Table
| Unit | m² | ft² | Acres | Hectares |
|---|---|---|---|---|
| 1 ft² | 0.0929 | 1 | 0.0000230 | 0.00000929 |
| 1 m² | 1 | 10.764 | 0.000247 | 0.0001 |
| 1 yd² | 0.8361 | 9 | 0.000207 | 0.0000836 |
| 1 are | 100 | 1,076.4 | 0.02471 | 0.01 |
| 1 acre | 4,047 | 43,560 | 1 | 0.4047 |
| 1 hectare | 10,000 | 107,639 | 2.4711 | 1 |
| 1 km² | 1,000,000 | 10,763,910 | 247.105 | 100 |
| 1 mi² | 2,589,988 | 27,878,400 | 640 | 258.999 |
South Asian Land Measurement Units — Marla, Kanal, Bigha
South Asian countries use traditional land measurement units that persist alongside the metric system in legal documents, real estate listings, and everyday conversation. These units are essential for buyers and sellers in Pakistan, India, Bangladesh, and Nepal.
| Unit | Region | ft² | m² | Acres |
|---|---|---|---|---|
| 1 Marla | Pakistan, Punjab India | 225 | 20.903 | 0.005165 |
| 1 Kanal | Pakistan, Punjab India | 4,500 | 418.064 | 0.10313 |
| 8 Kanal | Pakistan | 36,000 | 3,344.5 | 0.82503 ≈ 1 acre |
| 1 Bigha (pucca) | UP, Bihar, West Bengal, Raj | 27,225 | 2,529.3 | 0.625 |
| 1 Bigha (kuchha) | Bihar, some UP areas | 9,075 | 843.1 | 0.2083 |
| 1 Bigha (Punjab/Haryana) | Punjab, Haryana India | 9,068 | 842.5 | 0.2082 |
⚠️ Important regional note: The bigha has different values in different Indian states. Always confirm which state definition applies. For legal property transactions, always use the official definition from the relevant state revenue or land registration authority. The kanal and marla values above are the Pakistan Board of Revenue standard definitions used in Punjab, KPK, and Sindh.
Real-World Size References
| Area | sq ft | m² | Acres | Real-World Context |
|---|---|---|---|---|
| Studio apartment | 350–500 | 32–46 | 0.008–0.011 | Small city flat |
| Average US home | 2,300 | 214 | 0.053 | Typical suburban house |
| Tennis court | 2,808 | 261 | 0.064 | Singles court |
| Basketball court | 4,700 | 437 | 0.108 | NBA regulation |
| Quarter-acre lot | 10,890 | 1,012 | 0.25 | Typical suburban lot |
| American football field | 48,000 | 4,459 | 1.10 | Including end zones |
| Soccer field (FIFA) | 69,440–82,600 | 6,450–7,669 | 1.59–1.90 | FIFA regulation range |
| 1 Acre | 43,560 | 4,047 | 1 | Football field without end zones |
| 1 Hectare | 107,639 | 10,000 | 2.471 | 100m × 100m square |
| Central Park, NYC | 14,000,000+ | 1,300,000 | 843 | Iconic city park |
Acre vs Hectare — Which to Use?
The acre is the dominant land measurement unit in the United States, United Kingdom, Canada, Australia, and much of the Commonwealth. The hectare is the international metric standard used in Europe, Africa, Asia, and by international organisations including the UN for agricultural statistics. One hectare is exactly 2.471054 acres, making it approximately 2.5 times larger than an acre. For international property comparisons, always check which unit a listing uses — a 5-hectare property is about 12.4 acres, a significant difference if you mistake one for the other.
Frequently Asked Questions
Exactly 43,560 square feet per acre. This is defined as 1 furlong (660 ft) × 1 chain (66 ft) = 43,560 sq ft. To convert acres to sq ft, multiply by 43,560. To convert sq ft to acres, divide by 43,560. A quarter-acre lot = 10,890 sq ft.
Multiply sq ft by 0.09290304 exactly. This exact NIST factor comes from 1 ft = 0.3048 m, squared: 0.3048² = 0.09290304. Example: 1,000 sq ft × 0.09290304 = 92.90 m². Reverse: multiply m² by 10.76391042 to get sq ft.
One hectare = 2.47105381 acres. One acre = 0.40468564 hectares. A hectare is 10,000 m² (100m × 100m). To convert hectares to acres, multiply by 2.47105. To convert acres to hectares, multiply by 0.40469.
One acre is 43,560 sq ft — roughly the size of an American football field (without end zones). It is approximately 70m × 57m if square-shaped. 640 acres = 1 square mile. A quarter-acre (10,890 sq ft) is a typical US suburban residential lot. One acre = 0.4047 hectares.
Exactly 20 marla = 1 kanal per Pakistan Board of Revenue standard. 1 marla = 225 sq ft = 20.903 m². 1 kanal = 4,500 sq ft = 418.064 m². 8 kanal ≈ 1 acre in Pakistan land measurement. These definitions apply in Punjab, KPK, and Sindh.
The pucca bigha (standard in UP, Bihar, West Bengal, Rajasthan) = 0.625 acres = 27,225 sq ft = 2,529.285 m². The kuchha bigha = 1/3 pucca bigha. Punjab/Haryana bigha = 9,068 sq ft (different definition). Always confirm the state-specific definition for legal transactions.
Exactly 10,000 square metres in 1 hectare. A hectare is defined as 100m × 100m = 10,000 m². It is the primary metric unit for land area, used globally for agricultural statistics, forestry, and real estate outside the US and UK.
Exactly 640 acres in one square mile. This is a fixed US survey definition: 1 mi² = 5,280 ft × 5,280 ft = 27,878,400 sq ft ÷ 43,560 sq ft/acre = 640 acres exactly. A US township is 6 miles × 6 miles = 36 square miles = 23,040 acres.
Forgetting to square the conversion factor. If 1 ft = 0.3048 m, then 1 ft² = 0.3048² = 0.09290304 m² (not 0.3048 m²). Doubling a square’s side quadruples its area. Always use the squared factor for area conversions — this is a NIST-documented common error.
Multiply km² by 0.386102159 to get mi². Reverse: multiply mi² by 2.58998811 for km². These exact factors come from 1 mile = 1.609344 km (NIST 1959), so 1 mi² = 1.609344² = 2.58998811 km². Example: 100 km² = 38.61 mi².
Acres are the primary land measurement unit in: United States, United Kingdom (where the hectare is now official but acres remain common), Canada, Australia, Jamaica, India (alongside bigha/marla), and Pakistan (alongside kanal/marla). Hectares are used in: all of continental Europe, most of Asia, Africa, Latin America, and for all international agricultural and environmental reporting by UN agencies.
100 m² = 1,076.39 square feet. Use the exact factor: 100 × 10.76391042 = 1,076.39 sq ft. A 100 m² apartment is equivalent to approximately a 10.5 metre × 9.5 metre floor plan. This is a common conversion for international property comparisons.
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