Swimsuits are designed to be snug fit or closely fitted to your skin to take up your body shape. But more often than most, people end up with the wrong size when purchasing a swimsuit. As a matter of fact, it is the highest cons of swimsuit products. This can be more than frustrating. So, what do you do when you get the wrong bathing suit? Can you alter a swimsuit?
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If a swimsuit is too big or small, it is possible to alter or tailor it to achieve a better fit. You can even attempt to do DIY swimsuit alterations for your one-piece bathing, swimsuit bottoms, or bathing suit leg openings, provided that you are feeling adventurous.
Let’s start with a swimsuit that’s too big, you can fix it with the following steps
- Try it on to see if it’s too big
- Adjust the straps to see what changes they bring to the overall fit.
- Take it off and fold the areas you’ve marked with another pin.
- After making the right adjustments, put it on again to check the new size if it now fits as it should.
Now, let’s go through the reasons for altering a swimwear and show you the practical guide on how to alter swimsuits that are too big or too small.

3 Reasons For Altering A Swimsuit
1. It is too big
This is the first and commonest reason why people decide to get it with their swimsuit. You may have recently lost weight, or you saw a very good one at a discounted price and you couldn’t care less about the size.
2. It’s too small
Being too big is ultimately bearable, but being too small is rather painful. Don’t lose hope, but the solution lies in that old swimsuit that has been lying around the house without much thought. If the materials are the same or similar, hoorah, but if not, then a little manipulation on the sides can still pull it off unnoticeably.
3. It’s too boring
If the design or tone of your swimsuit came seems redundant or you are tired of the same look as your old swimsuit, there is something you can still do about it to re-awaken its glamour.
You can transform a high-waisted bottom into one with a low-waisted pair, or convert your two-piece into a one-piece, the stage is yours.
How to Alter Swimsuit That is Too Big in 4 Simple Steps

If you got a swimsuit you’ve been eyeing for so long, and when it finally came, it didn’t fit, don’t fret. As I mentioned earlier, if you have sewing experience, all you need is a needle and thread to re-transform your favorite swimsuit to your size.
Step 1: Try it on
Yes, try it on again, it’s not to confirm if it’s too big or small, you already know that, but try it on again to know how much it’s too big. This is where you need accurate measurements to work with, you can use a pin to hold the loose, extra part, and when you take it off, you can mark the area with chalk. And at this stage, make sure you are not wearing anything underneath, it can give you the wrong measurements.
NOTE: Trying it on without underwear doesn’t mean you shouldn’t add a little extra if you are the type that doesn’t wear swimsuits without undergarments.
Step 2: Adjust the straps
If your swimsuit has straps, try adjusting them to see what changes it brings to the overall fit. Take note of the areas that sagging or gapping, especially the bottom. Depending on where the gaps are, gather the elastic seam at the legs or waist and pin it to fit.
Step 3: Take it off
Now, you’ve got what you need to adjust in your big swimsuit, take it off and fold the areas you’ve marked with another pin. Then, double-stitch the folded parts in place.
Step 4: Try it on again
After making the right adjustments, put it on again to check the new size if it now fits as it should. If it doesn’t or there are still some adjustments to be made, repeat all the steps till you arrive at the right size.
How to Alter Swimsuit That is Too Small
On the other hand, if it is too small, it requires a bit of attention. Making swimsuits bigger isn’t easy, and unlike many garments that come with their in-built seam allowance, swimsuits have no excess fabrics. You are going to need to get creative at this point, and that means getting acquainted with the concept of panels.
Panels change the design of a swimsuit, and if wisely done, they can produce beautiful results. Panels can add to the general aesthetics and give it a little breathing room. To go on, you will need a fabric of the same stretch as your swimsuit, or you can dabble around with whatever is available. Then use the following steps.
- Add and pin the panel
- Sew it on the fabric
- Stitch the seam between the swimsuit and the panel
Step 1: Add and pin the panel
Do this, by simply cutting out a precise length of fabric you want to add to your swimsuit. After cutting the fabric along the seam for accurate fitting, pin the panel in place, and sew it on.
To prevent minor puckers, be careful of how you stitch the seam between the swimsuit and the panel, then you’re done, and you have a little more space for comfort.
How to Alter Boring Swimsuit
If your swimsuit is too boring, try out any of these amazing ideas.
- Reform the straps
- Convert your one-piece into a high-waisted bikini
- Make your bottom look cheekier
1. Reform the straps
If the top of your swimsuit is always sagging, or it’s too tight, making your breasts squeeze out through the armpit, altering the strap might be the solution.
You can shorten the straps using a sewing machine. If sewing is not suitable for you, you can alternatively snip the straps off the back of the swimsuit, then trim it to the length you want with a halter tie at the neck. Cutting it shorter is easier, but you can add a bit of length in the same vein.
2. Convert your one-piece into a high-waisted bikini
You may love the design of your one-piece suit, but you are ready to move on to new ones and embrace the newer glamour of a high-waisted bikini. Change the look of your favorite suit to form a retro bottom. Simply pair your suit with a bikini top and step out in class.
3. Make your bottom look cheekier
A few playful alterations will ruched up the back of your bikini bottom. This move would descend your bum more and you won’t be able to get over the eyes escorting you from behind. Also, you don’t need more than your emergency sewing kits to get it up, or perhaps the hotel kit would do it just fine as well.
How to Alter a Swimsuit by Hand
Altering a swimsuit by hand can be a bit challenging due to the stretchy nature of the fabric, but with patience and the right tools, you can do it. Here’s a step-by-step guide on how to alter a swimsuit by hand:
- Put on the swimsuit you want to alter and determine the adjustments needed.
- Lay the swimsuit flat on a clean surface, with the right side facing up.
- Pin the fabric together along the lines you’ve drawn, making sure the fabric is smooth and free of wrinkles.
- Begin sewing along the lines you’ve marked, being careful to keep the fabric taut and the stitches even.
- Secure the thread by tying a knot close to the fabric and trimming away any excess.
Can You Really Alter Swimsuit Bottoms?
Yes, swimsuit bottoms can be altered if they are too big or small. Depending on the material and how stretchy the bathing suit is, there are a variety of alterations that can be made, such as:
How to Alter Swimsuit Bottoms in 3 Easy Steps
To alter swimsuit bottoms, there are a few methods you can try:
- Adjust the waist to create a better fit.
- Shorten the length desired length.
- Adjust the leg openings by taking in or letting out the seams.
1. Adjust the waist
Start by turning the bottoms inside out and trying them on to determine where you need to take them in. Pin the excess fabric or elastic at the sides of the waistband, making sure to keep the pins parallel to the existing seam.
Next, use a sewing machine or needle and thread to sew along the pinned edges, creating a new seam that is closer to the body. Once you’ve sewn the new seam, try on the swimsuit bottoms to check the fit.
2. Shorten the length
Start by measuring the length you want to remove, and mark that measurement on the fabric. Next, fold the excess fabric up to create a hem, making sure to fold it evenly on both sides. Pin the hem in place, and use a sewing machine or needle and thread to sew along the pinned edge, creating a new seam. Once you’ve sewn the hem, try on the swimsuit bottoms to check the length.
3. Adjust the leg openings
Turn the bottoms inside out and try them on to determine where you need to adjust the fit. Pin the edges of the fabric or lining together and use a sewing machine or needle and thread to sew along the pinned edges. Then try on the swimsuit bottoms to check if it fits.
How to Tighten Bathing Suit Leg Openings
- Use elastic for a stretchy material like spandex or nylon.
- Take in the seams for materials such as cotton or polyester.
- Tie the sides for swimsuits with ties on the sides, such as bikini bottoms.
1. Using elastic
Cut a piece of elastic that is slightly shorter than the circumference of the leg opening. Then, fold the elastic in half lengthwise, and pin the ends together to create a loop.
Next, pin the loop of elastic to the inside edge of the leg opening, with the folded edge of the elastic facing inward. Sew the elastic to the fabric and stretch the elastic slightly as you sew to create a snug fit.
Once you’ve sewn the elastic all the way around the leg opening, trim any excess fabric or elastic from the edges. Repeat on the other leg opening, and try on the bathing suit to check the fit.
2. Take in the seams
Turn the bathing suit inside out, and pin the edges of the lining or fabric together around the leg opening, creating a smaller circumference. Sew along the pinned edges, taking care not to sew through both layers of fabric.
Turn the bathing suit right side out, and try it on to check the fit. If the leg openings are still too loose, you can repeat the process, taking in the seams a little more each time until you achieve the desired fit.
3. Tie the sides
Simply adjust the ties to create a tighter fit around the leg openings. Tie the strings in a double knot to keep them in place, and trim any excess string.
Yes, a swimsuit can be tailored to fit your body type.
Yes, bikini bottoms can be altered to improve fit and comfort. Adjustments may include taking in the sides, tightening the waistband, or adding elastic to the leg openings.
Yes, you can hem a bathing suit. It is another means of altering a bathing suit. Use a stretch stitch, such as a zigzag stitch or a twin-needle stitch, to accommodate the fabric’s elasticity and ensure a secure, durable hem. Can you tailor a swimsuit?
Can bikini bottoms be altered?
Can you hem a bathing suit?
Conclusion on Bathing Suit Alteration
Yes, swimsuits can accommodate minor and major changes, however, you choose to redefine them. Whether too big, small, or boring, you have all you need to set it in motion. Swimsuits are meant to be smug fit, so any other way should have it adjusted. We always encourage DIY methods to boost personal development, but you can always get help should you feel you need it.

Your step-by-step guide was a revelation. I love how you broke down the alterations based on common fit issues. It’s like having a personal swimsuit tailor at my fingertips.