Square Feet Calculator: Area & Carpet Area Converter

A square foot (sq ft) is the standard unit for measuring property area in India. This free calculator converts between square feet, square meters, gaj, marla, bigha, guntha, cent, and other Indian land measurement units. It also calculates carpet area from super built-up area as mandated by RERA.

Use Calculator

Enter length and width to calculate area in square feet and other units.

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Total Area

1,200 sq ft

Square Meters

111.48 sq m

Square Yards

133.33 sq yd

Gaj (गज)

133.33 gaj

Marla (मरला)

4.41 marla

Acres

0.0275 acre

Formula

30 × 40

Common Room Sizes in India

1 BHK Flat

400-600 sq ft

2 BHK Flat

700-1000 sq ft

3 BHK Flat

1200-1800 sq ft

Bedroom

120-150 sq ft

Kitchen

60-80 sq ft

Bathroom

35-45 sq ft

Living Room

150-250 sq ft

Car Parking

120-180 sq ft

How to Calculate Square Feet

Calculating area in square feet is fundamental to every property transaction in India. Whether you are buying a flat in Mumbai, a plot in Jaipur, or agricultural land in Kerala, understanding area measurements is essential. The formula is simple: Area (sq ft) = Length (ft) × Width (ft). For rooms measured in feet and inches, convert inches to decimal feet first — for example, 12 feet 6 inches = 12.5 feet.

For irregularly shaped rooms or plots, divide the area into rectangular sections, calculate each section's area separately, and add them together. For triangular sections, use: Area = ½ × Base × Height. For circular areas (like a cylindrical column), use: Area = π × radius². Most property areas in India, however, are rectangular and the simple length × width formula suffices.

Indian Land Measurement Units Explained

India uses a variety of land measurement units that vary by region. This creates confusion, especially for buyers purchasing property in a different state. Here is a comprehensive guide:

North India: Gaj, Marla, Kanal, Bigha

  • Gaj (गज): 1 gaj = 1 square yard = 9 square feet. Used extensively in Delhi-NCR, Uttar Pradesh, Rajasthan, and Haryana. When someone says "200 gaj plot," they mean 200 × 9 = 1,800 sq ft.
  • Marla (मरला): 1 marla = 272.25 sq ft = 30.25 sq yards. Common in Punjab, Haryana, and Himachal Pradesh. A "5 marla house" = 1,361 sq ft, and "10 marla" = 2,722 sq ft.
  • Kanal (कनाल): 1 kanal = 20 marla = 5,445 sq ft. Used in Punjab, J&K, and Himachal Pradesh for larger plots. 1 kanal is approximately ⅛ of an acre.
  • Bigha (बीघा): Varies by state. In UP and Rajasthan, 1 bigha ≈ 27,000 sq ft. In West Bengal, 1 bigha ≈ 14,400 sq ft. In Gujarat, 1 bigha ≈ 17,427 sq ft. Always confirm the local standard.

West India: Guntha, Acre

  • Guntha (गुंठा): 1 guntha = 1,089 sq ft. Used in Maharashtra and Karnataka, especially for agricultural land. 40 guntha = 1 acre.
  • Acre: 1 acre = 43,560 sq ft = 4,840 sq yards. Used across India for large land parcels. In Maharashtra, 1 acre = 40 guntha. In Tamil Nadu, 1 acre = 100 cents.

South India: Cent, Ground, Ankanam

  • Cent (सेंट): 1 cent = 435.6 sq ft. Used in Kerala, Tamil Nadu, and parts of Karnataka. 100 cents = 1 acre. A common residential plot in Kerala is 5-10 cents (2,178-4,356 sq ft).
  • Ground (ग्राउंड): 1 ground = 2,400 sq ft. Used exclusively in Tamil Nadu, especially Chennai. Property prices in Chennai are often quoted per ground.
  • Ankanam: 1 ankanam = 72 sq ft. Used in Andhra Pradesh and Telangana. 1 acre = 605 ankanam.

Carpet Area vs Built-Up Area vs Super Built-Up Area

Understanding the difference between these three area measurements is critical when buying property in India. Before RERA, many developers quoted prices on super built-up area, inflating the apparent size by 30-45%. RERA now mandates carpet area pricing.

Type Includes Typical %
Carpet AreaUsable floor area only (inside walls)60-75% of super built-up
Built-Up AreaCarpet area + wall thickness + balcony80-90% of super built-up
Super Built-Up AreaBuilt-up + share of common areas (lobby, stairs, lift, pool, gym)100% (base)

Under RERA, check the carpet area on the RERA portal for the exact registered carpet area of your unit.

Common Property Sizes in India

Here are typical property sizes to help you visualize square footage:

Property Type Carpet Area Range Super Built-Up Range
Studio / 1 RK200-350 sq ft300-500 sq ft
1 BHK350-500 sq ft500-700 sq ft
2 BHK600-850 sq ft850-1,200 sq ft
3 BHK950-1,400 sq ft1,400-2,000 sq ft
4 BHK / Penthouse1,500-3,000 sq ft2,200-4,500 sq ft
Independent House1,000-5,000 sq ftN/A
Plot (30×40)1,200 sq ft = 133 gaj = 4.4 marla
Plot (40×60)2,400 sq ft = 267 gaj = 8.8 marla = 1 ground

Related Tools

Calculate the full cost of buying property with our other free tools: Stamp Duty Calculator for registration costs, EMI Calculator for home loan planning, and RERA Project Lookup to verify project registration. Browse all free tools.

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Square Feet & Area Calculation: FAQ

To calculate square feet, measure the length and width of the room in feet, then multiply them. For example, a room that is 12 feet long and 10 feet wide is 12 × 10 = 120 square feet. If you measure in feet and inches, convert inches to a fraction of feet first (e.g., 12 feet 6 inches = 12.5 feet). For irregular shapes, divide the area into rectangles, calculate each separately, and add them together.

1 square foot equals 144 square inches. This is because 1 foot = 12 inches, and 1 square foot = 12 inches × 12 inches = 144 square inches. Conversely, to convert square inches to square feet, divide by 144.

A 30×40 site is 1,200 square feet. This is a very common plot size in Indian cities, especially in Bangalore, Mysore, and other Karnataka cities. In terms of other units: 1,200 sq ft = 111.48 sq meters = 133.33 sq yards = 133.33 gaj = 4.41 marla.

Carpet area is the actual usable floor area inside your apartment — the area where you can lay a carpet. It excludes walls, balconies, and common areas. Super built-up area includes carpet area + wall thickness + balcony area + your proportionate share of common areas (lobby, stairs, lift, corridors, gym, swimming pool area). Super built-up area is typically 25-40% more than carpet area. Under RERA, developers must sell on carpet area basis.

1 gaj = 1 square yard = 9 square feet. To convert square feet to gaj, divide by 9. For example, 1,200 sq ft = 1,200 ÷ 9 = 133.33 gaj. Gaj is commonly used in North India (Delhi, UP, Rajasthan, Haryana) for property transactions, especially for plots and land.

1 marla = 272.25 square feet (or approximately 25.29 square meters). Marla is commonly used in Punjab, Haryana, and Himachal Pradesh. 1 kanal = 20 marla = 5,445 square feet. A typical residential plot in Punjab is 5 marla (1,361 sq ft) to 10 marla (2,722 sq ft).

1 bigha varies by state but is most commonly 27,000 square feet (in UP, Bihar, Rajasthan). In some states like West Bengal, 1 bigha = 14,400 sq ft, and in Gujarat, 1 bigha = 17,427 sq ft. Always clarify which standard applies in your state when dealing with bigha measurements. This calculator uses the most common standard of 27,000 sq ft per bigha.

Carpet area = Super built-up area × (1 - loading factor). The loading factor varies: 25-30% for low-rise apartments (up to 4 floors), 30-35% for mid-rise (5-15 floors), and 35-45% for high-rise towers (15+ floors) with premium amenities. For example, if super built-up area is 1,500 sq ft with a 30% loading factor: Carpet area = 1,500 × 0.70 = 1,050 sq ft. Always ask the developer for exact carpet area as registered with RERA.

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