What this calculator does
One square foot equals 144 square inches, because a foot is 12 inches on each side and area scales by the square of the side length (12 × 12 = 144). This square inch calculator converts a value in either unit into the other, so a small area measured in square inches can be compared against a room or material spec quoted in square feet, or vice versa.
The mix-up worth avoiding is treating the conversion as linear, the way length converts from inches to feet by dividing by 12. Area does not work that way: dividing an area in square inches by 12 gives a meaningless figure, since area scales by the square of the linear ratio, which is why the correct factor is 144, not 12.
The formula
To go from square inches to square feet, divide by 144. To go from square feet to square inches, multiply by 144. The factor comes directly from 12 inches per foot squared (12² = 144), and never changes.
| Term | Meaning |
|---|---|
| Square inch (in²) | The area of a square measuring one inch on each side. |
| Square foot (ft²) | The area of a square measuring one foot on each side, equal to 144 square inches. |
| Conversion factor | A fixed constant: 1 ft² = 144 in², derived from 1 ft = 12 in squared. |
The inputs explained
| Field | What to enter |
|---|---|
| Area value | The area you want to convert, in the unit shown by the direction selected below. |
| Convert | Choose whether you are converting from square inches to square feet, or the other way round. |
When to use it
Sizing small materials against a per-square-foot price
Tile samples, stickers, glass panes and similar items are often measured in square inches, while flooring, glass and cladding are commonly priced per square foot. Converting the smaller unit up lets you apply that per-square-foot rate correctly.
Checking a spec sheet in the unfamiliar unit
A product datasheet quoted in square inches can be converted straight to square feet to compare against a room measurement or coverage requirement given in the more common unit for that job.
Working with an unusual document or screen size
Print and display areas are occasionally quoted in square inches; converting to square feet makes it easier to reason about compared with room-scale measurements such as a wall or floor area.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
Common square inch amounts converted to square feet
A range of square inch values converted to their square foot equivalent.
| Square inches | Square feet |
|---|---|
| 72 in² | 0.5000 ft² |
| 144 in² | 1.000 ft² |
| 288 in² | 2.000 ft² |
| 720 in² | 5.000 ft² |
| 1,440 in² | 10.000 ft² |
| 2,880 in² | 20.000 ft² |
Common square foot amounts converted to square inches
A range of square foot values converted to their square inch equivalent.
| Square feet | Square inches |
|---|---|
| 0.5 ft² | 72.00 in² |
| 1 ft² | 144.00 in² |
| 2 ft² | 288.00 in² |
| 5 ft² | 720.00 in² |
| 10 ft² | 1,440.00 in² |
| 20 ft² | 2,880.00 in² |
Questions
How many square inches are in a square foot?
There are 144 square inches in one square foot. This comes from a foot being 12 inches, and area scaling by the square of that linear factor: 12 × 12 = 144.
Why is the area conversion factor 144 and not 12?
Length converts from feet to inches by multiplying by 12, but area is two-dimensional, so both the length and width dimensions each get multiplied by 12, giving 12 × 12 = 144 for the area factor.
How do I convert square feet to square inches?
Multiply the square foot value by 144. For example, 3 square feet equals 3 × 144 = 432 square inches.
Does this conversion factor ever change?
No. It is a fixed geometric relationship between the inch and the foot, not a measured or estimated value, so it applies exactly the same way every time regardless of what is being measured.
For area conversions in metric units, see the square feet to square metres converter. For a linear inch-to-foot conversion, use the site search to find the relevant length converter.