Feet to yards (ft to yd)

One foot is exactly 0.3333333333 yards. That ratio belongs to the customary system itself and is much older than any link to metric: the 1959 international yard and pound agreement later fixed the yard and the pound against the meter and the kilogram, but it left the ratios between customary units (feet to the yard, ounces to the pound, cups to the gallon) exactly as they were.

Worked through: 12 ft x 0.333333333 = 4 yd.

Going the other way, one yard is 3 feet.

For mental arithmetic: Divide by 3.

Three feet to the yard, and the only reason this needs a page is what happens in two and three dimensions. Carpet, concrete and fabric are all sold by the yard, but carpet by the square yard, concrete by the cubic yard and fabric by the linear yard, so the same word takes the factor 3, 9 or 27 depending on the material. Measuring a room in feet and ordering in square yards means dividing by 9, and dividing by 3 is the most common and most expensive mistake in flooring estimates.

Precision is worth matching to the input. A measurement given as 3 ft carries one or two significant figures, and reporting its conversion to six implies a precision the original never had.