Square Area Calculator

Calculate the area of a square from side length, perimeter, diagonal, or known area. Get square feet, square inches, square yards, square meters, perimeter, diagonal, side length, and estimated material cost.

Calculate Square Area

Square Area = Side × Side. Perimeter = 4 × Side. Diagonal = Side × √2.
Your result will appear here.

How the square area calculator works

Side length mode:
The calculator multiplies the side length by itself to find the square area.

Perimeter mode:
The calculator divides the perimeter by 4 to find one side, then squares that side length.

Diagonal mode:
The calculator uses the diagonal to estimate side length, area, perimeter, and conversions.

Known area mode:
The calculator converts a known area into square feet, square inches, square yards, square meters, acres, and other useful results.

Why use a square area calculator?

A square area calculator helps estimate the size of a square space for flooring, concrete, tile, paint, landscaping, garden beds, rooms, patios, and construction planning.

It can help calculate total square footage, compare area units, estimate material quantity, add extra waste, and estimate project cost.

What your result means

Your result shows the square area, side length, perimeter, diagonal, area with extra waste, estimated pieces or units needed, and estimated cost based on the values you enter.

Square area formulas

Frequently asked questions

How do I calculate the area of a square?

Multiply one side of the square by itself. For example, a square that is 12 feet on each side has an area of 12 × 12 = 144 square feet.

What is the formula for square area?

The formula is Area = Side × Side, also written as A = s².

How do I find square area from perimeter?

Divide the perimeter by 4 to find the side length. Then multiply the side length by itself.

How do I find square area from diagonal?

Divide the diagonal by the square root of 2 to find the side length. Then square the side length to get the area.

Should I add extra waste for materials?

Yes. For flooring, tile, pavers, sod, mulch fabric, concrete forms, and other materials, adding 5% to 15% extra is common for cuts, mistakes, and layout waste.