Square Footage Calculator
Find the area of a rectangular, triangular, circular, or L-shaped space in square feet — the starting number for ordering flooring, paint, tile, or sod, with the formula shown so you can trust the result.
How to Use
- Pick the shape that matches your space — rectangle, triangle, circle, or L-shape.
- For a rectangle, enter length and width; for a triangle, the base and height.
- For a circle, enter the diameter; for an L-shape, the two length/width pairs that make up the two rectangles.
- Enter all dimensions in feet so the result comes out in square feet.
- Read the area and the formula used in the Show Work section below.
Show Work
Formulas
About the Square Footage Calculator
The Square Footage Calculator gives you a fast, free answer for building, materials estimation and site work without sending anything off your device. Find the area of a rectangular, triangular, circular, or L-shaped space in square feet — the starting number for ordering flooring, paint, tile, or sod, with the formula shown so you can trust the result.
How it works
Enter your figures and the result appears instantly, updating the moment you change anything. There is no submit button and nothing to wait for, so it is easy to try a few what-if numbers and compare the results. Just check each box holds the kind of value it expects.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
How do I find the square footage of an odd-shaped room?
Break it into simple shapes — rectangles, triangles, and partial circles — calculate each, and add them up. An L-shaped room is just two rectangles, which this tool handles directly. For a bay or rounded nook, treat it as a half or quarter circle and add it to the main rectangle.
What is the formula for each shape?
A rectangle is length × width, a triangle is ½ × base × height, and a circle is π × (diameter ÷ 2)². An L-shape is the sum of two rectangles. This calculator applies the right formula automatically and shows the math, so you can double-check it against your own numbers.
Should I round my measurements?
Measure to the nearest inch and convert to feet (divide inches by 12) rather than rounding to whole feet — a few inches across a long wall adds up. When ordering materials it is safer to round the final area up, then add the waste percentage your material calls for on top.
How do I convert square feet to square meters or square yards?
One square foot is 0.0929 square meters, so multiply square feet by 0.0929 for meters. To get square yards, divide square feet by 9. Carpet and some flooring are sometimes priced by the square yard, so the divide-by-9 conversion comes up often.
Does this measure walls too, or just floors?
It measures any flat area, so it works for walls as well as floors — just enter the wall length and height instead of room length and width. For painting or wallpapering a whole room, add up each wall, then subtract door and window openings before ordering material.
How do I use the Square Footage Calculator?
Just type your numbers. The answer shows up right away — there is no button to press. Change anything and it updates by itself.
Does it cost anything or need an account?
No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.
Is anything I type uploaded?
No. The tool works entirely on your device, so the values you enter never leave your browser.
Common Use Cases
Measuring a room for flooring
Get the floor area in square feet as the starting point for ordering tile, hardwood, or carpet.
Sizing paint coverage
Calculate wall area so you can divide by a paint coverage rate and buy the right number of gallons.
Calculating an irregular room
Use the L-shape mode to handle a room that bends without resorting to graph paper.
Pricing per square foot
Know the area to multiply by a per-square-foot material or labor rate for a quick estimate.
Measuring a yard or patio
Find the square footage of an outdoor area for sod, pavers, gravel, or a concrete pour.
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