Area Calculator
With length 12 ft, width 10 ft, area comes to 120.00 sq ft — area. It is reached in 4 steps, the last of which is shape_rectangle ? a_rectangle : shape_square ? a_square : shape_triangle ? a_triangle : shape_heron ? a_heron : shape_circle ? a_circle : shape_sector ? a_sector : shape_ellipse ? a_ellipse : shape_trapezoid ? a_trapezoid : shape_parallelogram ? a_parallelogram : a_polygon, and each one is printed on the page with its numbers filled in. The formula is the one published by Wolfram MathWorld, not an approximation fitted to it.
Area of a rectangle, triangle, circle, sector, ellipse, trapezoid, parallelogram or regular polygon — in square feet, square yards, acres and square meters.
Formula and sources checked · How we check
Shape Rectangle, Length 12 ft, Width 10 ft
120.00 sq ft
Area for the example below. Editing a field recomputes the calculator below; this figure holds the answer the page was loaded with.
It is written into the HTML rather than drawn by a script, so a search engine reading this page without running JavaScript still finds an answer.
- Area
120 sq ft- Square yards
120 / 913.333 sq yd- Acres
120 / 435600.003 ac- Square meters
120 * 0.09290311.148 m²
Several at once
A job is rarely one of anything. Work out the first, add it, change the figures and add the next — the list keeps what each line was, and totals them.
Worked example
A room 12 ft by 10 ft is 120 square feet. That is 13.33 square yards, which is the number a carpet supplier quotes in, and 11.15 square meters, which is the number a European listing gives.
How to work it out yourself
- 1.Pick the shape. A room with a bay window is two shapes added together, not one awkward one.
- 2.Measure the perpendicular height for a triangle, a trapezoid or a parallelogram. The sloping side is longer and gives an answer that is too big.
- 3.Add a waste allowance before ordering flooring or turf: the calculator gives the area, not the amount to buy.
The formula
- Area
- Square yards
120 / 9 - Acres
120 / 43560 - Square meters
120 * 0.092903
Source: Wolfram MathWorld — plane geometry, NIST Handbook 44, Appendix C — general tables of units of measurement
Questions people actually ask
- How many square feet are in a square yard?
- Nine. A yard is three feet, and area goes as the square, so three by three. That factor of nine is the reason a carpet quote and a room measurement can look wildly different for the same floor — and the reason to check which unit a price is per before comparing two of them.
- How do I find the area of an odd-shaped room?
- Cut it into rectangles and triangles, work each one out and add them. That is what a surveyor does, and it beats any single formula for an L-shaped room or a bay. Where a curve is involved, a sector handles the round end and a rectangle handles the rest.
- Can I find a triangle’s area without knowing its height?
- Yes, from the three sides, using Heron’s formula: half the perimeter, minus each side in turn, multiplied together and square-rooted. Choose the three-sides mode above. It is the practical one outdoors, where measuring a perpendicular height to a sloping corner is far harder than measuring three edges with a tape.
- Why is an acre 43,560 square feet?
- Because it was a chain by a furlong — 66 feet by 660 feet — the strip a team of oxen could plough in a day. The odd number is inherited rather than designed, and it is exact: an acre is 43,560 square feet by definition, not by approximation.
- What is a "square" in roofing?
- One hundred square feet. Shingles are sold and quoted by the square, so a 2,400 square foot roof is 24 squares before waste. It is a trade unit, not a standard one, and it exists nowhere else in construction.
Related
- Square Footage CalculatorSquare footage of a room, wall, border, gable end, ring or triangle from feet-and-inches measurements, with a waste factor and the cost.
- Circle CalculatorArea, circumference and radius of a circle from its diameter — in square feet and square inches.
- Right Triangle CalculatorHypotenuse, area, perimeter and both acute angles of a right triangle from its two legs, with the Pythagorean step shown before the square root.
- Arc Length and Sector Area CalculatorArc length, sector area, chord and sector perimeter from a radius and an angle, with the fraction of the full circle shown as its own step.
- Surface Area CalculatorSurface area of a box, cube, cylinder, sphere, cone, pyramid, capsule or ellipsoid, with the lateral area given separately from the ends.
- Triangle CalculatorEvery angle, the area, the perimeter and the height of any triangle from its three sides, using the law of cosines.
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