A round chair can be difficult to cover because you must also create the rounded portion of the chair cover, and sewing rounded pieces is more difficult than sewing flat pieces. Therefore, you need to make a cover in a certain way so it fits well onto the rounded top and does not fall off. You will want to sew a chair slip cover so you can cover the back of round chairs without having to nail or attach the chair cover.

Measurements

Take measurements to make the cover for your rounded chair back. You must have a measurement of the flat pieces of the chair back as well as the rounded pieces, so use a tape measure that is designed for sewing. You should have a length for both sides of the back of the chair, as well as a bottom width. Then, you should have a curved width. Take the measurement for the curved width in a slightly different way. Instead of measuring the distance only around the curve, take a flat piece of paper up to the chair back and trace the curve itself. Then you can make a copy of both the three straight edges and the curved edge. Trace these measurements exactly on sewing tracing paper. Proceed to make the cut out for your chair back. However, do not simply cut out the exact size and shape of the chair back. Add 1 inch to all the measurements. Do this by measuring out 1 inch from the flat sections, except for the bottom piece. Retrace those lines. Measure out 1 inch along various points of your curved section, and use a protractor to make sure you have the curve exactly. Then, cut out your tracing-paper chair back.

Sewing

Cut two pieces of fabric that are exactly the same size as your tracing paper cut out. Sew these first along all of the edges. Sew them together with a sewing machine. Do not sew the small flat section at the bottom. You should then have a chair cover that is the exact measurement of your chair, with enough room in it for your entire chair back to fit.

Source:

Upholster