How to Calculate Upholstery for a Sofa

Disassemble the sofa cushions with scissors and a sharp knife. Separate each piece, lay it out and measure the length and width at the widest points. Multiply length times width for each section to determine the square inches for that piece. Add the totals for each cushion and keep track on a list. Pin a note to each piece identifying which pillow it goes to so it's easier to reassemble the cushions after you copy the pieces with new fabric.

Take apart the rest of the upholstery panels and remove them from the sofa frame. Label the pieces and pin a note to the frame where they came from so you'll know where to put the new ones. For oddly shaped pieces, measure the sides at the widest points to determine length and width. Again, pin notes to the sofa frame to identify which pieces go back. Multiply length times width in inches to determine the square inches of fabric in each piece.

Write down the total square inches of each fabric panel and add them to the cushion totals. Don't forget to measure the bottom. Some sofas use a special gauze or black backing material there. Track its measurement and calculate separately from the upholstery fabric.

Convert the total number of square inches of material to square yards by dividing by 1,296. Do not stop here, however. If you are replacing your sofa fabric with a solid color, you'll be pretty close. Upholstery fabric often comes in 54-inch widths and is measured and sold by the yard for length so there is actually 1-1/2 yards of fabric per purchased "yard." To cover waste for solid patterns, buy an extra yard for every 6 yards you need For prints or stripes, use a different formula.

Measure how often the fabric pattern repeats horizontally for patterns or stripe. With patterns you must also measure how often the pattern repeats vertically as well and add the figures. Repeats tend to occur in increments of 3 inches (3, 6 ,9, 12, 15, 18, etc.) due to the way the manufacturing process works. If you are working with a standard 54-inch-wide fabric, add 10 percent to the total yardage if the pattern has a 3-to-14-inch repeat, 15 percent for 15-to-19 inch repeats, 20 percent for 20-to-27 inch repeats and 25 percent for 28-to-36 inch repeats. Few fabrics have a repeat larger than 27 inches. To calculate a pattern with a 6-inch horizontal repeat (10 percent) and a 15-inch vertical repeat (15 percent), add the two together (10 + 15 percent). Purchase an extra 25 percent of fabric to match the pattern and center it. The fabric shop will have wastage charts for other widths of fabric and can help you if you bring good measurements.