Calculate square footage for rectangles, circles, triangles, and trapezoids. Add multiple rooms, see a visual preview, and get paint, tile, and carpet estimates.
What is Square Footage Calculator?
A powerful square footage calculator that goes beyond simple length × width. Choose from four shapes (rectangle, circle, triangle, trapezoid), add multiple rooms or areas with custom names, and see a live SVG preview of each shape with labeled dimensions. Toggle between feet and meters, view per-room breakdowns, and get practical estimates for paint gallons, flooring tiles, carpet square yards, and cost at a customizable price per square foot. Also useful for estimating roof square footage for roofing projects.
How to Use
Select a shape (rectangle, circle, triangle, or trapezoid)
Enter dimensions in feet or meters
Add more rooms with the "Add Area" button
View total square footage and practical estimates below
Frequently Asked Questions
How do I calculate an L-shaped room?
Break it into two rectangles and add each as a separate area. The calculator totals them automatically.
How accurate are the paint estimates?
We use the industry standard of 1 gallon per 350 sq ft for one coat. Multiply by the number of coats you plan to apply.
Can I mix feet and meters?
The unit toggle applies to all rooms. Switch units and all dimensions convert automatically in the calculation.
Related Tools
🧱 Concrete Calculator — Calculate how much concrete you need for slabs, walls, and columns. Shows cubic yards, bags needed, and estima
% Percentage Calculator — Calculate percentages instantly — find X% of Y, percentage change, increase/decrease by %, and what percent X
🔄 Unit Converter — Convert between units of length, weight, temperature, speed, and data size instantly.
🎂 Age Calculator — Free age computation tool — calculate age from date of birth in years, months, days, hours, and minutes with f