Square Footage Calculator
Calculate the area of a room, floor, wall or simple shape. Enter the measurements you can actually take on site, and see the result in square feet, square meters and square yards.
Measure the area
For a room, measure wall to wall. Each measurement has its unit beside the number.
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Enter measurements to calculate.
How to calculate square footage, formulas, examples & FAQs
How to use the square footage calculator
- For a rectangular room, measure the inside length from wall to wall.
- Measure the width from the other wall to the opposite wall.
- Choose feet, metres or another unit that matches how you measured.
- Add another rectangle when a floor plan has multiple simple rooms or sections.
- For irregular shapes, split the area into simple rectangles or use the triangle/circle options where appropriate.
Square footage formula
The calculator converts the finished area to square feet, square meters and square yards after calculating each shape in square metres internally.
Worked example
Area = 12 × 10 = 120 ft².
That is approximately 11.15 m² or 13.33 yd².
How to measure a room for square footage
Measure the usable inside dimensions where the floor actually extends. For a rectangular room, take the longest wall-to-wall distance as length and the other wall-to-wall distance as width. For a room that is not rectangular, split it into smaller rectangles, calculate each area, and add them together.
Square feet vs square meters
Square feet (ft²) and square meters (m²) are both units of area. ToolVault keeps the complete calculation precision internally and rounds only the displayed values.
Accuracy and limitations
This calculator measures geometric area. It does not decide how much paint, flooring, tile, concrete or other material you should buy. Those products need their own coverage, waste, thickness or installation assumptions. For construction takeoffs, verify field measurements and project drawings before ordering materials.
Frequently asked questions
How do I calculate the square footage of a room?
Measure the room length and width in the same units, then multiply length × width. If the room is irregular, divide it into simple sections and add their areas.
How many square feet are in a square meter?
One square meter equals 10.7639104167 square feet.
How do I calculate square footage from feet?
Multiply the length in feet by the width in feet. A 12 ft × 10 ft room is 120 square feet.
What if my room is not a rectangle?
Split the floor plan into rectangles, triangles or other simple shapes that you can measure, then add the areas.
Can I add multiple rooms?
Yes. The rectangle mode lets you add multiple rooms or areas and gives one combined total.