4 Square Feet to Square Yards

Four square feet is 0.444444 square yards

Nine square feet to a square yard

Four square feet is 0.444444 square yards. The sum is one division: 4 / 9 = 0.444444. The same patch is 576 square inches, or 0.37161216 square meters.

A square yard is a square three feet on each side, so nine square feet fit inside it. That single fact drives the whole conversion. To go from square feet to square yards you divide by 9. To go back you multiply by 9.

The metric values are fixed by definition, not measured. The NIST Guide to the SI, Appendix B.9 lists the square foot at 0.09290304 square meters and the square yard at 0.83612736 square meters, both in bold type, which marks an exact factor. The BIPM SI Brochure, 9th edition, 2019 fixes the inch at exactly 25.4 millimeters, so a foot is 0.3048 meters and a square foot is 0.3048 x 0.3048.

Read the table from the middle out. Any row can be rebuilt from the square foot row, and the square yard row is the one most quotes use.

Divide by 9, and the reason it is not 3

Length squares, area does not

The factor is 9 rather than 3 because area grows with the square of length. One yard is three feet, and 3 x 3 = 9. In metric the same step runs through the meter: 0.9144 x 0.9144 = 0.83612736 square meters for the square yard, and 0.3048 x 0.3048 = 0.09290304 for the square foot. Divide one by the other and the answer lands on 9 exactly.

Worked example, out and back. Four square feet divided by 9 is 0.444444 square yards. Multiply 0.444444 by 9 and the answer is 4 again. In metric, 4 x 0.09290304 = 0.37161216 square meters, and 0.444444 x 0.83612736 = 0.37161216, which is the check that both routes agree.

Worked example with a bigger patch. A rug that measures 6 feet by 6 feet covers 36 square feet. Divide by 9 and it is 4 square yards. In metric, 36 x 0.09290304 = 3.34450944 square meters, and the same rug is 6 feet, or 1.8288 meters, on each side.

Two mistakes come up often. Dividing by 3 instead of 9 turns 4 square feet into 1.333333 square yards, which is three times the real area. Squaring the number as well as the unit turns 4 square feet into 16, which would be a patch 4 feet on each side. A patch 4 feet on each side holds 16 square feet, four times the area asked about here.

What 4 square feet looks like on the floor

Same area, several shapes

Four square feet is a square 2 feet on each side. That is about the size of a chair seat, a doormat, a single shower tile panel, or the floor of a small dog crate. It is small enough that most people overbuy material for it, and small enough that the shape matters as much as the number.

Area does not care about shape. Any rectangle whose length times width is 4 holds the same four square feet. The same holds for a circle 2.2568 feet across, though most flooring is sold in rectangles and strips.

Order material in the shape you plan to lay. A 1 foot by 4 foot strip wastes less carpet than a 2 foot square if the roll is 12 feet wide, and the reverse is true for tile, where square cuts leave fewer offcuts.

Carpet and vinyl priced by the square yard

What the invoice shows

Carpet, vinyl and most sheet flooring are priced by the square yard in the United States, so this is the conversion that shows up on a real invoice. Take a price of $27.00 a square yard. Four square feet is 0.444444 of a square yard, and 0.444444 x 27 = $12.00. The same material is $3.00 a square foot, because 27 / 9 = 3.00.

Worked example on a roll. Carpet usually comes 12 feet wide, which is 4 yards. One linear yard of that roll covers 4 square yards, or 36 square feet. Four square feet is one ninth of that strip, so it takes 4 / 12 = 0.333333 linear feet, or 4 inches, off the end of the roll. Most shops will not cut a 4 inch strip, which is why small patches are often sold as remnants.

Worked example with the bigger patch. The same 36 square feet at $27.00 a square yard is 4 x 27 = $108.00. Add ten percent for cuts and the order becomes 4.4 square yards, which bills at $118.80.

Watch the unit on the quote. A price of $3.00 a square foot looks cheaper than $27.00 a square yard until you multiply by 9 and find they are the same number.

Tile counts and paint for a patch this small

Pieces and fluid ounces

Tile is sold by the piece and paint by the gallon, so a 4 square foot patch needs a count rather than a decimal. The counts below assume square tiles set edge to edge with no grout line, then add ten percent for cuts.

Paint is the odd one. Four square feet at 350 square feet a gallon is 0.011429 gallons, and 0.011429 x 128 = 1.46 fluid ounces. Nobody sells that, so a sample pot or a quart is the real purchase. Two coats double the figure to about 2.9 fluid ounces.

Grout adds a little. A 1/8 inch joint on 4 inch tiles adds roughly 4 percent to the surface count, so 40 tiles covers the waste and the joints together.

Concrete, mulch and topsoil by the inch

Area times depth

Concrete, mulch and topsoil are sold by volume, so the area has to be multiplied by a depth first. The formula is square feet times depth in inches, divided by 12, which gives cubic feet. Divide that by 27 for cubic yards.

Worked example, concrete. Four square feet at 4 inches deep is 4 x 4 / 12 = 1.3333 cubic feet, or 0.049383 cubic yards. An 80 pound bag of concrete mix yields about 0.6 cubic feet, so 1.3333 / 0.6 = 2.22 bags, which means buying three.

Worked example, mulch. The same patch at 2 inches is 4 x 2 / 12 = 0.6667 cubic feet. That is 1.11 bags of the 0.6 cubic foot size, or one 2 cubic foot bag with some left over.

Bag counts are rounded up at the store, never down. A pour that needs 2.22 bags gets three, and the leftover sets in the bucket unless you have another use for it.

Square feet to square yards, one chart

Sizes from one tile to a small room

Most of these jobs arrive as a list of areas in square feet, and the quote is in square yards. The chart below covers the sizes that show up on a typical order sheet, from a single tile to a small room.

The 9 square feet row is the anchor. Everything above it is a fraction of a square yard, and everything below it is a whole number plus a fraction. A 90 square foot room is exactly 10 square yards, which is why contractors like room sizes that divide by 9.

Acres, square meters and the repeating decimal

Four numbers to keep

Four square feet is a small slice of an acre. One acre is 43,560 square feet, so 4 / 43,560 = 0.0000918274 acre. In square yards the same slice is 0.444444, and one acre is 4,840 square yards, so 0.444444 / 4,840 lands on the same decimal.

The square root is worth knowing because it tells you the shape of a square patch. The square root of 4 is 2, so a square of 4 square feet is 2 feet on each side, or 24 inches. The square root of 36 is 6, so a 36 square foot patch is 6 feet on each side.

Four numbers cover almost every use of this page. One square yard is 9 square feet. One square foot is 144 square inches. One square foot is 0.09290304 square meters. One acre is 43,560 square feet. Keep those four and any area in this family converts without a calculator.

One last check on rounding. The exact value of 4 / 9 repeats forever as 0.444444 and so on. Rounded to four decimals it is 0.4444, and that is what most quotes show. Rounding to two decimals gives 0.44, which understates the area by about one percent, so order material from the longer decimal and round up at the end.