Square Footage Calculator for Irregular Rooms
Calculate area for rectangles, triangles, circles, and L-shaped rooms, with results in square feet, meters, yards, and acres.
Measuring a room for flooring, paint, or real estate listings starts with knowing the exact area, but most rooms are not perfect rectangles. This square footage calculator handles rectangles, triangles, circles, and L-shaped rooms, then converts the result into square meters, square yards, and acres automatically. It is built for homeowners planning renovations, contractors estimating materials, real estate agents listing square footage, and students working through geometry problems. For irregular spaces like L-shaped living rooms or multi-room layouts, the custom polygon mode lets you break the area into rectangle segments and add them together, with a visual diagram showing how the shape is constructed. Getting this number right also matters when ordering flooring, paint, or carpet, since underestimating leads to mid-project shortages and overestimating wastes money on unused material. Every input updates the result instantly, so you can experiment with dimensions without resetting the form. Once you have a final number, copy it directly to your clipboard for quotes, listings, or purchase orders.
Room Shape
120.00 sq ft
Sq Meters
11.15
Sq Yards
13.33
Acres
0.0028
How to Use This Calculator
1. Choose your room shape
Select Rectangle, Triangle, Circle, L-Shape, or Custom Polygon.
2. Enter the dimensions
Use feet for all measurements. L-shapes and custom rooms use multiple rectangle segments.
3. Review the diagram
L-shaped rooms show a visual diagram so you can confirm the layout matches your space.
4. Copy your result
Use the copy button to paste the square footage into a quote, listing, or order form.
How It Works
Rectangle
Length × WidthA 12 ft × 10 ft room equals 120 square feet.
Triangle
0.5 × Base × HeightA 12 ft base with 8 ft height equals 48 square feet.
Circle
π × Radius²A 6 ft radius circle equals about 113.1 square feet.
L-Shape
(L1 × W1) + (L2 × W2)A 12x10 section plus a 6x5 extension equals 150 square feet.
Frequently Asked Questions
How do I calculate square footage for an irregular room?
Break the room into smaller rectangles, calculate the area of each one, then add the areas together. The custom polygon mode in this calculator does this automatically when you enter each segment's length and width.
How do I calculate square footage for an L-shaped room?
Split the L-shape into two rectangles, the main section and the extension. Multiply length by width for each rectangle, then add the two results together. For example, a 12x10 main section and a 6x5 extension gives 120 + 30 = 150 square feet.
How many square feet are in an acre?
One acre equals 43,560 square feet. This calculator converts your entered area into acres automatically alongside square meters and square yards.
How do I convert square feet to square meters?
Multiply square feet by 0.092903 to get square meters. For example, 150 square feet equals approximately 13.94 square meters.
What is the formula for a circular area in square feet?
Area equals pi multiplied by the radius squared (π × r²). A circle with a 6 foot radius has an area of about 113.1 square feet.