To get inches to feet in terms of decimal, you divide the number of inches by 12 (the number of inches in a foot). The conversion of fractions of an inch (for example, 3/8”) is much the same. You take the fraction, and divide the top number by the bottom (to get a decimal value), then take the result and divide it by 12 (inches in a foot). A good table and calculator can be found at www.cleavebooks.co.uk/scol/ccftins.htm There’s also a useful video to help explain the uses of this conversion at www.youtube.com/watch?v=462l9qlVpAI This conversion is mainly used in construction, to easily add and check dimensions used when using standard building materials. Standard materials are often cut into lengths in feet, and, when being measured for, say, the length of a desk, the measurement itself is taken in inches. This is to get a greater specificity to measurement. The same theory is used in engineering, where everything is referred to in millimeters, when most people would use meters or centimeters, and so the reverse conversion would be needed. If you’re checking a string of dimensions to check they add up to the sum dimensions (in terms of architectural drawings and engineering drawings), you need to be able to convert the values quickly and easily, to be viewed in a commonly used format.
