Calculate square footage for rectangles, circles, and triangles, with an optional material cost, right in your browser.
Square Footage Calculator Online
Calculate square footage for rectangles, circles, and triangles, with an optional material cost, right in your browser.
The Square Footage Calculator runs entirely in your browser. The dimensions, quantity, and price you enter never leave your device and nothing is uploaded to ArrayKit.
The Square Footage Calculator finds the area of a room or project in square feet and square meters, then multiplies by quantity and an optional price to estimate material cost. Pick rectangle, circle, or triangle, choose feet or meters, and type in the measurements; the result always shows both square feet and square meters. Switching the unit does not convert numbers already typed; they are read in the new unit. It is built for flooring, tile, paint, carpet, turf, and other by-the-square-foot projects where you need a quick area and a rough budget before you shop. Add a quantity to cover multiple rooms of the same size, and a price per square foot or meter to see an estimated total cost. Everything runs locally in your browser, so your room dimensions never leave your device. Treat the total as an estimate — always re-measure and verify quantities before ordering materials.
Features
Calculates area for rectangles, circles, and triangles
Feet or meters toggle; numbers already typed are read in the new unit, not converted
Shows results in both square feet and square meters at once
Quantity field multiplies the area across identical rooms or sections
Optional price per unit area estimates total material cost
Copy a plain-text summary of the area and cost with one click
Clear error message for zero, negative or unreadable dimensions
Runs entirely in your browser — no room measurements are uploaded
How to use the Square Footage Calculator
Choose a shape: rectangle, circle, or triangle
Select feet or meters to match how you measured
Enter the dimensions for that shape
Add a quantity for multiple rooms and an optional price per unit area
Read the square footage, square meters, and estimated cost
Example
Input
12×10 ft, ×2 rooms
Output
240 sq ft
A 12×10 ft room doubled for two identical rooms totals 240 square feet.
Common errors & troubleshooting
Square footage looks ten times too small or too large. — Check the feet/meters toggle matches your tape measure: switching it re-reads the numbers you typed in the new unit instead of converting them.
The tool shows an error instead of a result. — Every dimension for the selected shape must be a number greater than 0; a blank or 0 field blocks the calculation.
Total cost seems off for a multi-room project. — The price per unit area is multiplied by area × quantity, so confirm the quantity reflects how many identical rooms or sections you are pricing.
Circle area does not match a rough estimate. — Enter the radius (half the diameter), not the diameter — the calculator uses π × radius² for circles.
Frequently asked questions
What is the Square Footage Calculator?
It is a tool that finds the area of a rectangle, circle, or triangle in square feet and square meters, then optionally multiplies by quantity and a price per unit area to estimate material cost.
How does the Square Footage Calculator handle circles and triangles?
For circles it uses π × radius², and for triangles it uses 0.5 × base × height, matching the shape you select before entering dimensions.
Can the Square Footage Calculator work in square meters instead of square feet?
Yes. Set the unit to meters and enter your dimensions in meters; the result always shows both square feet and square meters. Switching the unit does not convert numbers you have already typed, so pick the unit first.
Does the Square Footage Calculator estimate material cost?
Yes, if you enter a price per unit area it multiplies that by the total area (including quantity) to show an estimated total cost — useful for flooring, tile, or paint budgeting.
Is the Square Footage Calculator accurate enough to order materials?
It gives a solid planning estimate based on the numbers you type. Always re-measure the actual space and verify quantities, including waste allowance, before placing an order.
Does the Square Footage Calculator upload my room dimensions anywhere?
No. The Square Footage Calculator runs entirely in your browser — the dimensions, quantity, and price you enter never leave your device.
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