Square Footage Calculator
Find the square footage of any space for flooring, tiling, or turf, with cost from a price per square foot.
📐 What is the Square Footage Calculator?
The square footage calculator works out the area of a space in square feet, along with square metres and square yards, for the three shapes that cover almost every real project: rectangles, circles, and triangles. Add a price per square foot and it also returns the total material cost, turning a set of measurements into an order quantity and a budget.
It is one of the most reached-for tools in home improvement and construction. You need square footage to buy flooring, tile, carpet, turf, decking, or underlay; to price a concrete slab or a patio; and to estimate almost any material sold by area. A homeowner measuring a lounge for laminate, a landscaper quoting artificial grass, and a tiler pricing a bathroom all start with the same question: how many square feet is this space.
The core idea is simple but easy to get wrong in the details. Area is length times width for a rectangle, but every dimension must be in the same unit before you multiply, which is why this calculator lets you enter feet, inches, yards, or metres and converts for you. Odd shapes are handled by splitting them into simple pieces, calculating each, and adding the results. And because materials come in boxes and rolls, you should always add a waste allowance and round up.
This tool is useful because it removes the unit conversions and the shape formulas, and it ties area straight to cost. You measure, pick a shape and unit, and instantly see the area in three systems plus the total price, with the working shown so you can check it or adjust for waste.
📐 Formula
📖 How to Use This Calculator
Steps
💡 Example Calculations
Example 1 - Rectangular room, 12 by 10 feet
Example 2 - Circular patio, 20 feet across
Example 3 - Triangular section, base 15 ft, height 8 ft
❓ Frequently Asked Questions
🔗 Related Calculators
How do you calculate square footage?
For a rectangular area, multiply length by width with both in feet. A room 12 feet by 10 feet is 12 x 10 = 120 square feet. For a circle use pi times the radius squared, and for a triangle use half the base times the height.
How do I convert square feet to square metres?
Multiply square feet by 0.0929 to get square metres, or multiply square metres by 10.764 to go the other way. So 120 square feet is about 11.15 square metres. This calculator shows square feet, square metres, and square yards at once.
How many square feet are in a square yard?
There are 9 square feet in one square yard, because a yard is 3 feet and 3 x 3 = 9. To convert square feet to square yards, divide by 9. Carpet is often priced per square yard, so this conversion is handy when comparing flooring quotes.
How do I find the square footage of an odd-shaped room?
Break the shape into simple rectangles, and if needed circles or triangles, calculate the area of each part, then add them together. For a room with a bay window, treat the main rectangle and the bay separately and sum the two areas.
How much flooring should I buy for a room?
Calculate the room's square footage, then add 5 to 10 percent for waste from cuts and mistakes, and up to 15 percent for diagonal or herringbone patterns. Round up to whole boxes, since flooring is sold by the box covering a fixed area.
How do I calculate the cost of flooring or turf?
Multiply the area in square feet by the price per square foot. For 120 square feet at 5 dollars per square foot, the cost is 120 x 5 = 600 dollars. Enter a price in this calculator to see the total automatically alongside the area.
How do you calculate the square footage of a circle?
Use area = pi times the radius squared, where the radius is half the diameter. A circular patio 20 feet across has a radius of 10 feet, so the area is pi x 10 squared = about 314 square feet. Select the circle mode and enter the diameter.
Does square footage include walls or just the floor?
Floor square footage measures the floor area inside the walls, which is what you need for flooring and tiling. Wall area is a separate calculation for paint and drywall. Use the Wall Square Footage Calculator for painting, and this one for the floor.