Measuring and cutting out

With your measuring tape, take the four basic measurements of your sofa. Measure from the front to the back of the sofa for the body length, and measure from arm to arm across the sofa seat for the body width.
Measure from where the arm meets the seat and over the arm to the floor for the arm length. Measure from where the arm meets the front of the sofa seat to where the arm meets the sofa back for the arm width.
Main cover: The length of the main cover will be the sofa length plus 14in (36cm) for seam and tuck-in allowances. The width will be the body width plus twice the arm width, plus 14in (36cm) for seam and tuck-in allowances. Cut out of the main fabric.
Overlayer: Cut out three pieces from the contrasting fabric.
One piece measuring the body width and body length, adding 1.25in (32mm) all round for seam allowances, and adding 12in (30cm) onto the body length for the tuck-in allowances.
Two pieces to the arm width and arm length, adding 1.25in (32mm) all round for seam allowances and adding 12in (30cm) onto the arm length for the tuck-in allowance.

Sewing the main cover

Place the unfinished fabric on the sofa and place one corner level with the floor.
Drape the sofa to the desired shape - leaving any extra fabric to pool in the seat of the sofa - and trim the remaining corners flush with the floor.
Take the cover off the sofa. Turn under a 5/8in (16mm) hem all around and stitch. Press.
Drape the finished cover over the sofa so the front, back and side hems touch the floor. Tuck the extra fabric in the seat of the sofa behind the cushions.