Square Footage Calculator

Free square footage calculator supporting rectangles, circles, triangles, trapezoids, and custom shapes. Calculate room areas, estimate paint and flooring costs with waste factors. View results in square feet, square meters, acres, and hectares. Perfect for home improvement and real estate.

Measurement Unit

Length (ft)

Width (ft)

Area Formulas Reference

Rectangle

A = length x width

Circle

A = pi x r²

Triangle

A = 0.5 x base x height

Trapezoid

A = 0.5 x (a + b) x h

Heron's formula for triangles with three sides: s = (a+b+c)/2, then A = sqrt(s(s-a)(s-b)(s-c))

How to Use Square Footage Calculator

1Select a shape (rectangle, circle, triangle, etc.).
2Enter the dimensions in your preferred unit.
3View the area with automatic unit conversions.
4Use the cost estimator for flooring or paint projects.

Frequently Asked Questions

How do I calculate square footage?▾

For a rectangle, multiply length × width. For example, a 12ft × 15ft room = 180 sq ft.

How many square feet do I need for flooring?▾

Measure each room's square footage and add 10% for waste and cuts. The calculator does this automatically.

How do I calculate square footage of a circle?▾

Use the formula: Area = π × radius². Enter the radius or diameter and the calculator handles the math.

About Square Footage Calculator

NexTool's Square Footage Calculator is completely free to use with no sign-up required. Your data is processed directly in your browser and never sent to our servers, ensuring complete privacy and instant results.