The life of your swimwear really depends on its fabric and the environment you are wearing it in. There is a variety of fabrics used to make swimsuits but the two popular swimwear fabrics on the market are polyester and nylon/spandex (lycra)
Polyester swimwear fabric: This fabric is less stretched and has a tighter fit that some people find less comfort. If you choose this swimsuit fabric type, you should go for one or two sizes larger than your usual size in order to get more comfortable. If you swim frequently in a swimming pool where chemical or chlorine level is high, the 100% polyester would be ideal because the fabric would last for at least one year or two depending on frequency of use and how you care for your swimsuit.
Nylon: is the most common fabric for swimwear as it is more stretchy than polyester especially if it is mixed with spandex (lycra). It fits smoothly on the body. Nylon swimwear gets dry quicker than polyester swimwear as it absorbs very little moisture; the disadvantage is that a nylon swimsuit would not last long when it is exposed to sun or chemicals on a regular basis.
If you plan to do exercise in the water such as Aqua Aerobic (or Aquarobic/ Water Aerobic) or frequently use heated swimming pools; the chlorine plus the temperature will damage the nylon swim wear fabric quicker than if you wear a swimsuit made from polyester. Different kind of swimwear fabrics (colourfast; nylon/lycra; polyester…) were made for different purposes so you should choose the fabric which suits your purpose. Designer brands or unknown branded swimsuits (quality ones) would have the same lasting if you wear them in the right place and care for them.
Understanding the swimwear fabric types and taking good care will help you keep your favourite swimsuit last longer and in its prestige condition.