To take in a dress, subtract your waist and hip measurements from the dress' waist and hip measurements, and divide the results by four. Turn the dress inside-out, and mark that distance from the side seam at the waist and hip respectively. Sew a new seam through the marks.
- Determine how far to take in the dress
Measure your waist and hips. Lay the dress flat, and measure across the front and back of the corresponding waist and hip areas. Add the dress measurements together to get the total waist and hip measurements. Subtract your measurements from the dress' measurements to determine how many inches need to be removed.
- Mark your new seams
Divide the amount to be taken in at the waist by four. Turn the dress inside out, and place a mark at that distance from the seam at the waist of the dress on both the front and back of both sides. Repeat with the hip measurement.
- Sew the seam
Sew a neat line from the armpit through the two marks to the hip area of the dress. Keep the line as straight as possible. Leave the extra fabric as a large seam inside the dress. This allows the size to be adjusted easily.