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Square Footage Calculator

Everyday

Calculate square footage for rectangles, circles, triangles, and trapezoids with instant conversion to square metres and square yards as well.

Reviewed by the thecalcu.com team · Last updated July 9, 2026

Shape
12 ft
10 ft
Square Footage
—
sq ft
Square Metres
—
m²
Square Yards
—
sq yd
Area References
Cricket pitch1,120 sq ft
Standard room (10×12)120 sq ft
1 BHK flat (carpet)~550 sq ft
Tennis court2,808 sq ft
Conversions: 1 sq ft = 0.0929 m² = 0.111 sq yd = 144 sq in

What is a Square Footage?

A Square Footage Calculator computes the area of a space in square feet and automatically converts the result to square metres (m²), square yards (sq yd), and square inches (sq in). It supports four common shapes, rectangle, circle, triangle, and trapezoid, covering the vast majority of rooms, plots, and surfaces encountered in construction, real estate, interior design, and renovation planning.

Square footage is the dominant unit for residential real estate in Indian cities. Whether a broker quotes ₹8,500 per sq ft for a 2 BHK in Bengaluru or a builder lists a flat's RERA carpet area as 950 sq ft, the number is foundational to any property transaction. Independently verifying the carpet area, by measuring each room and computing the area, protects buyers from discrepancies between the declared area and the actual usable space.

Beyond real estate, square footage appears in tiling projects (how many tiles for a 120 sq ft room), interior design (how much paint or wallpaper for a 200 sq ft living room), construction planning (how large a concrete slab needs to be), and BTU calculations (what size AC is needed for a 180 sq ft bedroom). The Square Footage Calculator is the starting point for all of these downstream calculations.

Unit conversions are a frequent source of confusion. The Indian property market quotes carpet area in sq ft; European and international architecture standards use m²; traditional Indian land measurements (Biswa, Gunta, Cent) derive from sq yd. The calculator outputs all four metric and imperial area units simultaneously, eliminating manual conversion.

Why Use a Square Footage Calculator?

Verify RERA carpet area independently. RERA (Real Estate Regulation and Development Act) mandates that builders disclose and transact on carpet area. Buyers can measure each room and use the Square Footage Calculator to sum the areas and cross-check the declared carpet area before signing an agreement.

Convert between area units. Tenants comparing a flat quoted in sq ft with an international property quoted in m², or comparing a plot quoted in sq yd against a neighbouring one in sq m, need instant conversions. The calculator delivers all units at once.

Plan tiling and flooring. The carpet area in sq ft is the key input for calculating tile quantity, paint coverage, laminate flooring boxes, and similar materials. Use the Tile Calculator after this to convert area directly into purchase quantities.

Calculate BTU for air conditioning. Room area in sq ft is the primary input to the BTU Calculator for sizing an air conditioner. Measure the room with the Square Footage Calculator first.

Estimate from unusual shapes. Not every room is a rectangle. The circle mode handles round or octagonal spaces; the trapezoid mode handles rooms with non-parallel walls or sloped ceiling boundaries.

Who Should Use This Calculator?

Home buyers and property investors verifying carpet area of flats being considered for purchase, checking that the builder's area declaration matches what can be physically measured.

Interior designers and architects who need quick area computations during site visits, before measurements are formalized in AutoCAD drawings.

Renovation contractors pricing tile-laying, painting, or plastering jobs, which are typically quoted on a per-sq-ft basis in India.

Real estate agents who need to instantly communicate area in different units to buyers from different backgrounds, NRI buyers familiar with sq ft and m², domestic buyers familiar with sq yd and traditional units.

Homeowners planning a DIY project, painting a bedroom, selecting a carpet, tiling a bathroom, who need to buy materials accurately without overestimating or underestimating the area.

What Insights Does the Square Footage Calculator Give You?

Square Feet is the primary output, the area in the most commonly used unit for Indian residential real estate and construction material estimation.

Square Metres is the SI unit used in international property comparisons, European standards, and government records in India for plotted land development.

Square Yards is the traditional unit used in Indian fabric and carpet markets, in some regional land records (especially in Punjab, Haryana, and Gujarat), and in older construction documents.

Square Inches is useful for very small areas, tile samples, window panes, signage panels, where sq ft would be an impractically small decimal.

How to use this Square Footage calculator

  1. Select the Shape, choose Rectangle (for most rooms and plots), Circle (for round spaces or circular features), Triangle (for triangular plots, loft sections, or angled alcoves), or Trapezoid (for rooms with one pair of non-parallel walls).
  2. Enter the Dimensions, the calculator shows only the fields relevant to the selected shape. For rectangle: length and width in feet. For circle: radius in feet. For triangle: base and perpendicular height in feet. For trapezoid: bottom base, top base, and perpendicular height in feet.
  3. Read all four area units, Square Feet (primary), Square Metres, Square Yards, and Square Inches are all shown simultaneously. No further conversion is needed.
  4. Use the area as input elsewhere, take the sq ft figure into the Tile Calculator for flooring estimates or the BTU Calculator for AC sizing.

Formula & Methodology

Rectangle:
Area (sq ft) = Length (ft) × Width (ft)

Circle:
Area (sq ft) = π × Radius² = 3.14159265 × r²

Triangle:
Area (sq ft) = 0.5 × Base (ft) × Perpendicular Height (ft)

Trapezoid:
Area (sq ft) = 0.5 × (Bottom Base + Top Base) (ft) × Perpendicular Height (ft)

Unit Conversions:
Square Metres = sq ft × 0.092903
Square Yards = sq ft × 0.111111 (or sq ft ÷ 9)
Square Inches = sq ft × 144

Worked example: A buyer wants to verify the carpet area of a flat being quoted at 850 sq ft. They measure three rooms:

- Bedroom 1 (rectangle): 14 ft × 12 ft = 168 sq ft
- Bedroom 2 (rectangle): 12 ft × 11 ft = 132 sq ft
- Living + Dining (L-shape): divided into 18 ft × 14 ft (252 sq ft) and 8 ft × 10 ft (80 sq ft) = 332 sq ft
- Kitchen (rectangle): 10 ft × 8 ft = 80 sq ft
- Bathroom + WC: 6 ft × 5 ft = 30 sq ft (×2 bathrooms = 60 sq ft)
- Corridor/foyer: 8 ft × 4 ft = 32 sq ft

Total Carpet Area = 168 + 132 + 332 + 80 + 60 + 32 = 804 sq ft

The measured area (804 sq ft) is 46 sq ft less than the quoted 850 sq ft. The buyer should raise this discrepancy with the builder and verify the RERA-declared carpet area in the registered agreement before proceeding.

In square metres: 804 × 0.0929 = 74.7 m². In square yards: 804 ÷ 9 = 89.3 sq yd.

Frequently Asked Questions

Square footage is area measured in square feet. For a rectangle, multiply length (ft) × width (ft). For a circle, the area is π × radius² (in sq ft). For a triangle, area is 0.5 × base × perpendicular height. For a trapezoid, area is 0.5 × (bottom base + top base) × height. The Square Footage Calculator handles all four shapes and converts the result to square metres and square yards simultaneously.
Multiply square feet by 0.092903 to get square metres. For example, 1,200 sq ft = 1,200 × 0.0929 = 111.5 m². To convert from sq m back to sq ft, multiply by 10.7639. The Square Footage Calculator shows all unit conversions, sq ft, sq m, sq yd, and sq in, automatically for any shape and dimension you enter.
Carpet Area is the actual usable floor space inside the walls, the area you would measure with the Square Footage Calculator. Built-up Area includes carpet area plus the area of walls and columns. Super Built-up Area (also called saleable area) adds the proportional share of common areas, staircase, lobby, corridors, to the built-up area. RERA in India mandates that property prices be disclosed and sold based on carpet area.
1 square metre = 10.7639 square feet. Common reference: 10 m² = 107.6 sq ft; 100 m² = 1,076 sq ft; 1,000 m² = 10,764 sq ft. Indian property sizes in the RERA era are increasingly quoted in sq ft (for apartment carpet area) and in sq m (for plotted development). The Square Footage Calculator shows both simultaneously.
1 square yard = 9 square feet (since 1 yard = 3 feet, and 3² = 9). Square yards are still used for fabric, carpet, and tiling quotes in many parts of India. To convert sq ft to sq yd, divide by 9. The Square Footage Calculator outputs sq yd alongside sq ft for any shape.
Break the irregular shape into rectangles (or other standard shapes), calculate the area of each section using the Square Footage Calculator, and add the results together. For an L-shaped room, draw a line to create two rectangles, measure each separately, and sum the two square footages. The total is the combined carpet area.
Biswa is a traditional unit of land measurement used in north India (Uttar Pradesh, Bihar, Rajasthan). 1 Biswa = 125 square yards = 1,125 sq ft in the common UP convention, though the exact value varies by state, Haryana and Punjab use different Biswa sizes. Always verify the local Biswa-to-sq-ft conversion with the relevant state revenue records. Convert the result from the Square Footage Calculator to sq yd and then to Biswa using the local conversion.
Square footage (sq ft) is the dominant unit for quoting and transacting residential property in Indian cities. Builders quote price per sq ft on carpet area (as mandated by RERA) and total price is carpet area × rate per sq ft. The Square Footage Calculator helps verify the carpet area of a flat by measuring each room, corridor, and kitchen and summing the areas, a useful cross-check against the builder's RERA declaration.
Area of a trapezoid = 0.5 × (Bottom Base + Top Base) × Height, where height is the perpendicular distance between the two parallel bases. This formula applies to any trapezoid regardless of whether it is symmetric. A trapezoid-shaped plot of land or room section can be measured directly and entered into the calculator.
Area of a circle = π × radius² ≈ 3.14159 × r². For a circular garden with a 10 ft radius, area = 3.14159 × 100 = 314.16 sq ft = 29.2 sq m. In the Square Footage Calculator, select 'Circle,' enter the radius in feet, and get the area with all unit conversions in one step.
Use the Square Footage Calculator first to confirm the area of the room or surface in sq ft. Then take that sq ft figure and enter it directly into the [Tile Calculator](/tile-calculator/), or note the area and enter the room dimensions there, to get the number of tiles and boxes required for the flooring project. This two-step flow avoids re-measuring.
Also known as
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