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Square Feet Calculator

Calculate area in square feet for rectangles, triangles, circles, trapezoids, and map traces. Then estimate tile, flooring, concrete, or paint quantities.

Linear unit

Area

120.00 sq ft

11.15 sq m

ShapeRectangle
Formulalength × width

Need a change for Square Feet Calculator?

About this calculator

Method, formulas, and limits.

What this does

Computes square footage for common shapes (rectangle, triangle, circle, trapezoid, feet-inches mixed input) and traced map boundaries. It also estimates material quantities for tile, flooring, concrete, and wall paint from the computed area.

Who it is for

Homeowners measuring rooms, floors, yards, or driveways; contractors preparing bids; real estate professionals checking property dimensions; and DIYers planning tile, flooring, concrete, or paint purchases.

How it works

Select a shape and enter dimensions in feet, inches, meters, or centimeters. The area is computed in square feet and square meters simultaneously. The material panel then converts the area into tile counts, flooring boxes, concrete volume, or paint gallons using your inputs for waste, coverage, and cost.

Limitations

Map traces approximate the area of a traced boundary on a spherical surface; accuracy depends on the map zoom and trace precision. Material estimates assume rectangular tiles and planks and do not include pattern matching waste beyond your waste percentage.

Key calculations

Rectangle
length × width
Triangle
base × height / 2
Circle
π × radius²
Trapezoid
(base1 + base2) / 2 × height
Feet & Inches
length(ft+in) × width(ft+in)
Map Trace
Spherical polygon area from traced boundary points

Reference ranges

Room Sizes
A typical bedroom is 100-200 sq ft, a living room 200-400 sq ft, and a full house 1,500-2,500 sq ft.
Tile Waste
10% waste is standard for rectangular rooms. Diagonal layouts or complex cuts can need 15-20%.
Flooring Coverage
Laminate and hardwood boxes typically cover 15-25 sq ft per box. Always check the box for exact coverage.
Paint Coverage
One gallon of paint covers roughly 350 sq ft per coat. Two coats are standard for most rooms.

How to use it

  1. 1.Choose a shapePick Rectangle, Triangle, Circle, Trapezoid, Feet & Inches, or Map to match how you want to measure.
  2. 2.Enter dimensionsType the dimensions in the selected linear unit (ft, in, m, or cm). The area updates instantly in both square feet and square meters.
  3. 3.Trace a boundary (Map mode)Search an address, click points around the property on the map, then click Use area to send the traced area to the calculator.
  4. 4.Estimate materialsExpand the Materials panel and choose Tile, Flooring, Concrete, or Wall Paint. Enter the product details from the packaging to get quantities and cost.
  5. 5.Adjust wasteSet a waste percentage for tile (10% is typical) to cover cuts and breakage during installation.
  6. 6.Review resultsCheck the area in square feet and square meters, plus the material quantity and estimated cost.

Multiply length by width for rectangles. For triangles, multiply base by height and divide by 2. For circles, multiply π by the radius squared. The calculator handles all of these automatically.

One square meter equals 10.764 square feet. The calculator shows both units at once so you can work with whichever is more familiar.

Divide the room area by the area of one tile (including the grout gap), then add waste. The calculator does this automatically with the tile width, height, gap, and waste percentage you enter.

Divide the wall area by the coverage per gallon, then multiply by the number of coats. One gallon covers about 350 sq ft per coat.

Map tracing is accurate to the resolution of the map imagery and your click precision. It is best for rough estimates of lawns, driveways, and properties rather than precise construction measurements.

Yes. The Feet & Inches mode lets you enter whole feet and inches separately, which is convenient for US construction measurements.

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