Area Calculator

Measure the length and width of the room in feet using a tape measure, then multiply length by width. A 12 foot by 10 foot room is 120 square feet. For L-shaped rooms split the room into two rectangles, compute each area separately, and add them. The area calculator above handles rectangles, triangles, circles, trapezoids and L-shapes in one click.

Split the L into two rectangles. Measure the full length of the longest side, then the width of the shorter rectangle and the width of the longer rectangle. Compute area as (long_length times long_width) plus (short_length times short_width). For a more irregular shape add more rooms using the multi-room mode and let the calculator sum them.

One square foot equals 0.092903 square meters. Multiply your square foot area by 0.092903 to get square meters, or multiply square meters by 10.7639 to get square feet. The area calculator handles all conversions automatically when you toggle the unit switch at the top.

Measure the perimeter of the room (length plus width times 2) and multiply by the wall height in feet. Then subtract the area of every door (typically 21 sq ft) and window (typically 12 to 15 sq ft). One gallon of paint covers about 350 square feet of smooth drywall with one coat, or 175 square feet for two coats over primer.

A 10 foot by 10 foot room is 100 square feet. The same room in square meters is 9.29, in square yards is 11.11, and in acres is 0.0023. The area calculator above outputs all four units in one click when you toggle imperial or metric.

AI text models get the basic rectangle wrong when feet and inches are mixed (10 ft 6 in times 9 ft 4 in should be 98 sq ft, not 90), cannot decompose an L-shape into two rectangles, do not subtract doors and windows from wall area, do not convert between square feet and square meters reliably, and cannot estimate paint gallons or wallpaper rolls from area. They give a number that feels right but is off by 5 to 30 percent on real projects.

One square mile equals 640 acres, or 2.59 square kilometers, or 27,878,400 square feet. The area calculator handles every conversion above including acres, hectares, square miles, square kilometers, square yards and square meters in one click when you toggle units or enter the value in the converter panel.

Yes. Toggle the unit switch at the top to Metric and every input switches to meters and centimeters, area switches to square meters, paint switches to liters, and cost switches to the local currency. The math is the same; only the units and product sizes change. The conversion panel below the rooms section accepts any input and outputs all 8 unit systems in one row.

Yes. Everything runs in your browser using JavaScript. No room dimensions, area values, or costs are sent to any server. Close the tab and your last project is gone. The only data persisted is the last project in localStorage so the form reloads when you come back. There is no account, no email capture, no analytics tied to your project.