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By Chris Deziel
If you want to calculate the area of a space in square feet, it's best to express your measurements in feet. If you made the measurements in inches, one option is to convert the measurements to feet before calculating area. Another option is to make the calculation using inches, and then convert the result to square feet. Neither option is more difficult than the other, but converting to feet before calculating the area usually helps avoid having to deal with large, unwieldy numbers.
Square Feet TOTAL = Trestlewood makes no representations or warranties whatsoever relative to the accuracy of this calculator (or any of its other calculators) and accepts no liability or responsibility for results obtained from same. Sep 24, 2007 Best Answer: Well think of it this way. 5 ft by 5 ft is 25 square feet. The dimensions are just multiplied. 18.5 would be something like 4.25 by 4.25 or 3 by 6. Those aren't exact, but it could be anything that equals 18.5 when multipled. The square root of 18.5 is 4.3.
TL;DR (Too Long; Didn't Read)
Convert measurements from inches to feet by dividing by each measurement by 12. Then calculate the area using feet to get square feet. Alternatively, calculate the area in square inches and divide the result by 144.
Option 1: Convert to Feet Before Calculating Area
When you're looking for the area of a small item, it sometimes makes sense to make the measurements you need in inches. For example, suppose you want to cover a bathroom floor with small porcelain tiles, and you want to know the area of one tile to figure out how many you need. If you know the area of the bathroom floor, you'll probably have that figure in square feet, so it makes sense to calculate the area of the tile in square feet so you can divide its area into the area of the floor to obtain the number of tiles that will fit. However, the tiles are small, so you measured in inches.
In this case, divide each measurement you make in inches by 12 to convert it to feet. Once you have expressed the measurements in feet, you can calculate area in square feet.
Example: Suppose the tiles are square, and you measure the length and width of one of them to be 2 inches by 2 inches.
Divide each measurement by 12 to convert to feet and you find the tiles are 1/6 ft by 1/6 ft = 0.17 ft. x 0.17 ft.
Multiply these together to find the area of a single tile to be 1/36 sq ft = 0.0289 sq ft.
Option 2: Calculate Area in Square Inches and Convert
If you go ahead and calculate area in square inches, you can convert your result directly to square feet by dividing by 144. Why this number? Picture a square with an area of 1 square foot. Each side of the square is 12 inches long, and multiplying the lengths of the sides together produces an area of 144 square inches. So 1 square foot = 144 square inches.
Example: If you calculate the area in square inches of one of the 2-inch-square bathroom tiles in the example above, you'll find that each tile has an area of 4 sq in. Divide this number by 144 to arrive at the area in square feet: 4 sq in/144 = 0.0278 sq ft.
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By Chris Deziel
When you calculate square footage of rectangle, you're calculating its area. This is a simple math exercise with any number of real-world applications. A homeowner may want to know the size of a yard to plan a garden, a contractor may need to calculate the size of a room that needs new flooring or a painter may need to determine the size of a wall that needs painting. It's a calculation that requires two measurements: the length of the rectangle and its width, measured in feet. You determine the square footage by multiplying these measurements.
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![How much is 18 556 square feet How much is 18 556 square feet](/uploads/1/2/4/3/124331427/609093197.jpg)
TL;DR: The area of a rectangle, A, is given by the product of its length, L, and its width, W. The mathematical formula is A = LW.
Making Measurements
Before you calculate the area of a large space, such as your backyard or living room floor, it's important to make sure it's actually a rectangle. If it is, its two longer sides have exactly the same length. So do its two shorter sides. You can usually measure these with a tape measure. If one of the sides is longer or shorter than its opposing side, you can still use the formula to get an approximate figure. If the difference between the measurements of opposing sides is significant, though, you may have to divide the space into a rectangle and another geometric figure, such as a triangle. You can then calculate the areas separately and add them together.
Calculating Area of a Rectangle
Once you're sure the space is a true rectangle, the procedure for calculating the square footage is straightforward:
Measure the Dimensions
Convert to Decimal Notation
Calculate Area
Measure the length and width of the rectangle in feet and inches using a ruler or tape measure.
Make the calculation easier by converting the number of inches to a decimal fraction of a foot. You do this by dividing the number of inches by 12. For example, 5 inches = 5/12 = 0.42 feet, so a measurement of 13'5' = 13.42 feet. This step is optional, but it avoids the need to multiply fractions of 12, which can be complicated. It also allows you to do the calculation on a calculator.
Multiply the length and width together to calculate the square footage, or area, of the space.
Example: A homeowner wants to calculate the the square footage of the living room floor to determine how much flooring it will take to cover it. The length of the floor is 17'7' and the width is 12'3'.
Converting to decimals, the length and width are 17.58' and 12.25' Multiply to get the area 215.36 square feet.