What is square feet? It is a unit of area. One square foot is the flat patch inside a square whose sides each run 1 foot (12 inches). A floor, wall or lot is measured by counting how many of those patches would cover it. Singular or plural, the unit is the same, and you can shorten it to sq ft or ft².
Table of Contents
How big is one square foot
Lay four 12-inch rulers on a table so they form a square. The space they fence in is one square foot. Fill it with 1-inch squares and you get 12 rows of 12, which is 144 square inches.
Every figure in the table below is exact, taken from the tables of units in NIST Handbook 44, published by the National Institute of Standards and Technology (NIST).
| Unit | How it relates to a square foot |
|---|---|
| square inch | 1 sq ft = 144 sq in |
| square centimeter | 1 sq ft = 929.0304 cm² |
| square meter | 1 sq ft = 0.09290304 m² |
| square yard | 1 sq yd = 9 sq ft |
| acre | 1 acre = 43,560 sq ft |
A 120 sq ft room is about 11.15 m², and square feet to square meters has charts for both directions. A half acre holds 21,780 sq ft, and square feet to acres runs that division for any lot.
What is square feet in math
In math, square feet is a count of 1-foot squares. For a rectangle you never have to draw them. Length times width, both in feet, tells you how many 1-foot squares fit inside.
A bedroom 9 ft by 11 ft holds 9 rows of 11 squares, so its floor is 99 square feet. Real tape readings come in feet and inches, and the square footage calculator takes both without any converting on your part.
The squares do not have to fit whole. NIST's tables say area applies to irregular shapes as well as squares and circles. An L-shaped room gets split into rectangles first, as shown in finding the area of an irregular shape.
6 square feet vs 6 feet square
The two phrases swap the same words and mean different things. "6 feet square" names a shape: a square with 6-foot sides, which covers 36 sq ft. "6 square feet" names only an amount, and a 2 ft by 3 ft mat has it just as much as a 1 ft by 6 ft shelf. The small 2 in ft² belongs to the unit, so 6 ft² still means 6 square feet, never 6 times 6. When a homework problem or an ad uses either phrase, settle which one before you multiply.
Is square footage the same as area
Yes. Area is the amount of flat surface, and the meaning of square footage is that amount stated in one unit, the square foot. The same floor given in square meters is the same area under a different label.
A listing can still show less than a house's floor area, since a finished basement may sit outside the above-grade total, as does square footage include a basement explains.
The distance around the edge is a different measure. Take a garden bed 3 ft by 7 ft. It covers 3 x 7 = 21 square feet, yet edging it takes 3 + 7 + 3 + 7 = 20 feet of trim.
Is square feet a unit of volume
No. Volume needs a third measurement, depth, and the matching unit is the cubic foot. The table follows the same garden bed through all three kinds of measure after you fill it with soil 2 feet deep.
| Unit | Short form | What it measures | Garden bed |
|---|---|---|---|
| foot | ft | length | long side 7 ft; 20 ft of edging |
| square foot | sq ft, ft² | area | 3 ft x 7 ft = 21 sq ft |
| cubic foot | cu ft, ft³ | volume | 21 sq ft x 2 ft deep = 42 cu ft |
A cubic foot holds 1,728 cubic inches, since 12 x 12 x 12 = 1,728. To turn that 42 cu ft into cubic yards, use square feet to cubic yards.
Square foot, square feet or square footage
Say "square foot" for exactly one, "square feet" for any other number, and "square footage" for the total area of a place. All three are two words. Run together, "sqft" is a short form you see on web pages, while NIST writes sq ft.
The trap is the switch back to "foot" in front of a noun. Paul Brians makes the point with lumber in his usage guide: you can use eight-foot boards, yet each board measures eight feet. Area works the same way. You rent a 460-square-foot studio, the studio has 460 square feet, and the landlord quotes the square footage of the studio.
Square foot abbreviation and symbol
Write sq ft in everyday text and ft² in math, tables and science work. The table shows where each form turns up.
| Form | Kind | Where it turns up |
|---|---|---|
| sq ft | abbreviation | everyday text, NIST's abbreviation footnote |
| ft² | unit with a power of 2 | formulas, NIST's unit tables |
| cu ft, ft³ | cubic foot, for volume | NIST's volume table and abbreviation footnote |
| sf, SF, sq. ft., sqft | other short forms | floor plans, product listings |
Handbook 44 explains in a footnote that squares of U.S. customary units, unlike metric ones, are sometimes shortened with abbreviations in place of symbols.
Is square foot hyphenated
A number plus square foot usually takes hyphens when the phrase sits in front of a noun. The Chicago Manual of Style hyphenates "a 600-square-foot studio" because the phrase describes the studio. It leaves "a studio of 600 square feet" open because there the phrase is the thing being named. The table runs that rule on a 460-square-foot studio.
| Where the phrase sits | Write it like this | Hyphens |
|---|---|---|
| before the noun | a 460-square-foot studio | two, and "foot" stays singular |
| after the noun, as the amount | a studio of 460 square feet | none |
| stacked with another description | a 460-square-foot, fully furnished studio | two, plus a comma |
A single hyphen, as in "460 square-foot studio", leaves the number outside the compound. Chicago's square-foot examples carry two hyphens.
FAQ
Is sq ft the same as ft²?
Yes, the two forms name one unit and differ only in how they are written. A 99 sq ft bedroom is a 99 ft² bedroom. NIST calls sq ft an abbreviation and prints ft² in its tables, so use the first in a sentence and the second in a formula.
Are square foot and square feet the same unit?
Yes, foot and feet name one unit of one size, and only the count changes the word. One square foot covers 144 square inches, and each of the 99 square feet in a 9 ft by 11 ft bedroom covers the same 144. Use foot for exactly one and feet for other numbers, except in front of a noun.
Should sq ft be capitalized?
No, lowercase sq ft is the safe form, and it is how NIST prints the abbreviation in its handbook. Capital SF does turn up on floor plans, but NIST's tables do not use it. Keep the capitals only when you copy a plan's own label.
Is square feet bigger than feet?
No, the two cannot be ranked, because feet count length and square feet count surface. Comparing them is like asking whether a gallon beats a mile. A 3 ft by 7 ft garden bed shows it, with 21 square feet of soil inside 20 feet of edging.
What does 121 ft² mean?
121 ft² means 121 square feet of surface, whatever the outline. A room 11 ft by 11 ft has exactly that much floor, because 11 x 11 = 121. The small 2 marks the unit and never squares the 121.
What is the ⏍ symbol?
The ⏍ sign is a Unicode character named SQUARE FOOT, at code point U+23CD, so it is a real character and not a typo. NIST's tables leave it out and print ft² instead. Write ft² or sq ft, the two forms a reader can check against the handbook.
Conclusion
Before a figure goes on a form or a flyer, ask two questions: does it count surface, and does a noun follow it? If it counts surface, square feet fits, and a noun right after it usually brings the hyphens and the singular foot, as in a 460-square-foot studio. To get a figure for your own home, tape its outside walls, as measuring a whole house shows.
