How to Alter a Strapless Dress

    by Melissa J. Bell

    About the Author

    A writer with a Bachelor of Science in English and secondary education, but also an interest in all things beautiful, Melissa J. Bell has handed out beauty and fashion advice since she could talk -- and for the last six years, write for online publications like Daily Glow and SheBudgets.


    Today, the lack of customization in retail sizing often necessitates tailoring, and dress alterations can be fairly simple for those with a little sewing experience. Strapless dresses, in particular, are much more easily altered than types with sleeves and high necklines, especially if they do not include too many complex accessories. With a little measuring, marking and pinning, your strapless dress should be altered and ready to wear in no time at all.

    Things You'll Need

    • Pins
    • Fabric pencil
    • Seam ripper
    • Measuring tape
    • Matching thread
    • Sewing machine

    show more

    Determine what type of alteration your strapless dress needs. Usually, strapless dresses are taken in or out at the side seams to change the waist or hip measurements, taken up or down at the hem to change the length, and cut at the bust to increase or decrease the bust measurement. You will only be able to increase measurements slightly, depending on the length of the seam allowances inside the dress, so most dresses must be altered to be smaller.

    Alter the dress at the side seams. Put the dress on your body inside out and pinch the fabric in at the waist, hips and bust until the fit is better. Pin the pinches in place, then take the dress off. Adjust the pins so that you are taking off the same amount of fabric from each side of the dress. Using a fabric pencil, draw a smooth line on each side starting below your lowest pins, all the way up to your highest pins, at the point where you want to take the dress in. Pull out the side seam stitches with the seam ripper, then pin your fabric together. Stitch the side seams along your drawn lines.

    Change the hemline at the bottom of the dress. Tear out the existing hem stitching with a seam ripper, then put the dress on inside out and have a friend help you mark out a new hemline with pins. Take the dress off, and measure the distance between the edge of the fabric and the pins. Pin up the bottom edge of the fabric to the new hemline, making sure the hem is even by measuring as you go. Machine stitch the hem in place and remove the pins.

    Alter the dress at the bust. Take apart any seams at the front bodice, such as princess seams or underbust seams, and take them in or let them out, as necessary. Alter the side seams, if there are no princess or underbust seams to make the bust section of the dress fit. Place the dress on inside out and pull the seams to fit and pin in place. Mark the new seam area with a fabric pencil, drawing a smooth line and then remove the old seam with a seam ripper. Pin the seam back together, lining up your drawn lines and stitch the seams together. Remove the pins.

    Add spaghetti straps to the strapless dress, if desired. Get your strap length by putting on the dress and measuring from the front of the dress and over your shoulder to the back of the dress, where the straps should be placed. Mark the front and back portion of the dress where the straps attach using a fabric pencil. Measure and cut the straps so they are 2 inches longer on each end than you measurement, as this allows for seams. Pin each strap on the inside front and back of the dress, pinning at your pencil mark. Use a sewing machine to double stitch the strap in place and remove the pins.

    • If you are unsure if the dress will fit after making the alteration, make your first seam with a basting or larger seam than you would use for a permanent one. You can then easily remove the seam if more alterations are required. If the first seam fits and you used a basting seam, you can always sew over the basting seam with a smaller and more secure seam, leaving the basting seam in place.