Area and square footage calculator
Enter a room, slab, or lot and this returns the square footage, plus square yards and square meters in one read. Switch shapes for the area of a circle or the volume of a cylinder in cubic feet, cubic yards, and gallons. It runs the same area and volume math as the CutOnce app.
Updated
Area is length times width for a rectangle, or pi times the radius squared for a circle. Square feet is the working unit; square yards (÷9) is what flooring is ordered in, square meters (×0.0929) is the metric read.
- Square yards
- 18.67
- Square meters
- 15.61
- Square inches
- 24,192
How the area works
Square footage is length times width. A 12 by 14 room is 168 square feet, and that same number drives the order for flooring, paint, drywall, or a slab. The other units are just conversions of it: divide by nine for square yards, the unit carpet and other flooring are sold in, and multiply by 0.0929 for square meters. A circle is pi times the radius squared, where the radius is half the diameter a tape reads across the widest point. A cylinder is that circle area carried up its height, which is how a round tank, a culvert, or a fill gives its cubic feet and its gallons. Concrete is ordered in cubic yards, a volume, so a slab runs through the concrete calculator, not this square-yard read.
A worked example
A 12 ft by 14 ft room, the square footage read four ways. Here is where each number comes from.
| Square feet | 168.00 sq ft | 12 x 14 ft |
| Square yards | 18.67 sq yd | 168 / 9 |
| Square meters | 15.61 sq m | 168 x 0.0929 |
| Square inches | 24,192 sq in | 144 in x 168 in |
Rectangle, circle, or cylinder
The three shapes take their dimensions differently, which is why the calculator asks for the fields it does. Match your measurement to one of these.
| Shape | It takes | Result |
|---|---|---|
| Rectangle | Length and width | Area = L x W |
| Circle | Diameter (twice the radius) | Area = pi x (D/2)^2 |
| Cylinder | Diameter and height | Volume = pi x (D/2)^2 x H |
Converting between units
The same area or volume in the unit each trade orders in. These are the exact factors the calculator uses, so a square-foot figure and its square-yard figure always agree.
| 1 of this | equals |
|---|---|
| Square yard | 9 square feet |
| Square meter | 10.7639 square feet |
| Acre | 43,560 square feet |
| Cubic yard | 27 cubic feet |
| Cubic foot | 7.4805 US gallons |
What the app adds
This page sizes area and cylinder volume. The app enters each dimension in feet-inch-fractions the way a tape reads, adds a circle from its radius or circumference, keeps a running tape of results, and prints the takeoff as a material list. It also carries the estimating pages this feeds: concrete by the slab, drywall by the room, and roofing by the square.
Common questions
- How do I calculate square footage?
- Measure the length and the width in feet and multiply them. A 12 ft by 14 ft room is 168 square feet. For an L-shaped space, split it into rectangles, figure each one, and add them. The calculator does the multiply and the unit conversions so you can read the same room in square yards or square meters without redoing the math.
- How do I convert square feet to square yards?
- Divide by nine, because a square yard is 3 ft by 3 ft. So 168 square feet is 18.67 square yards. Carpet and other flooring are sold by the square yard, which is why the conversion comes up: a flooring quote in square yards is a square-foot measurement divided by nine. Concrete is different; it is ordered in cubic yards, a volume, not this area.
- How do I convert square feet to square meters?
- Multiply by 0.0929. A 168 square foot room is 15.61 square meters. Going the other way, a square meter is 10.7639 square feet, so multiply metric plans by that to read them in square feet.
- How do I find the area of a circle?
- Area is pi times the radius squared, and the radius is half the diameter. A 10 ft round patio has a 5 ft radius, so its area is pi times 25, about 78.54 square feet. Enter the diameter, the distance straight across the widest point, and the calculator halves it for you.
- How many gallons does a round tank hold?
- Figure the cylinder volume in cubic feet, then multiply by 7.4805 gallons per cubic foot; the calculator does both. A 4 ft diameter tank 6 ft tall holds about 564 gallons. The same volume in cubic yards is what you would order if you were filling it with concrete or fill instead of water.
- Does the calculator take feet and inches?
- This page takes each dimension in feet, so enter 12.5 for 12 ft 6 in. The CutOnce app takes the measurement in feet-inch-fractions the way a tape reads it, so 12 ft 6-1/2 in goes in as itself, which is the cleaner entry when you are working off a tape on the jobsite.
Measure once, order right
CutOnce figures the area like this page, then enters in feet-inch-fractions, keeps a running tape, and prints the takeoff as a material list, on the jobsite.
Free to download, with a 7-day trial of everything. The web calculator is the teaser; the app carries the full toolbox and works with no signal.
See also