Square Footage Calculator

Calculate the square footage of any room or space. Supports rectangle, triangle, circle, and trapezoid shapes. Great for flooring, painting, and real estate.

Part of our Math & Percentage Calculators collection.

Square Footage Calculator

Free online calculator

Shape

Length (ft)*

Width (ft)

Base (ft) — triangle/trapezoid

Height (ft) — triangle/trapezoid

Second Base (ft) — trapezoid only

Radius (ft) — circle

How to Use This Calculator

1
Select the shape of your room or space.
2
Enter the required dimensions in feet.
3
See the total square footage instantly.

Area Formulas

Rectangle: Length × Width
Triangle: (Base × Height) / 2
Circle: π × Radius²
Trapezoid: (Base1 + Base2) / 2 × Height

Example Calculation

Example: 12ft × 10ft rectangle

Inputs

shape: rectanglelength: 12width: 10

Result

120 sq ft

12 × 10 = 120 square feet.

Frequently Asked Questions

How do I calculate the square footage of an irregular room?

Break the room into rectangles, calculate each area separately, then add them together.

How much flooring do I need?

Calculate the square footage, then add 10% for waste and cuts. So a 120 sq ft room needs about 132 sq ft of flooring.