Joybuy Insights

Buying underwear online: how to choose the right fit, size and fabric

Buying underwear online may seem straightforward, but an attractive product photo tells you little about how comfortable it will be to wear. A waistband may start to dig in after a few hours, the wrong cut may show under clothing, and size labels can vary between brands or models. Whether you are shopping for women’s underwear, men’s underwear or shapewear, it pays to look beyond colour and price.

The most common pitfalls are:

  • Choosing a size based solely on S, M, L or XL. Body measurements and fit matter more than the letter on the label.
  • Confusing “seamless” with invisible or comfortable. Seamless underwear can still feel too tight if the fabric offers little give.
  • Treating marketing claims as guarantees. Terms such as “shaping”, “moisture-wicking” or “colourfast” should be checked against the materials, construction and care instructions.

Which specifications deserve attention?

1. Size and fit

Ideally, measure your waist where the waistband will sit and compare the measurement with the size chart for the specific product. High-waist briefs sit higher on the tummy than a low-rise model. This difference matters when you want to wear tummy-control underwear under a dress, trousers or skirt.

With men’s underwear, pay attention to the cut:

  • Men’s boxers: usually slightly longer on the thigh.
  • Men’s trunks: shorter legs and often a close-fitting shape.
  • Men’s hip briefs: cut lower around the hips.
  • Relaxed-fit trunks: offer more room than a fitted model.

Going up a size does not automatically make underwear more comfortable. With shapewear, too much room can cause the garment to roll up or fail to stay in place. A size that is too small can create pressure and visible lines.

2. Material and elasticity

For comfortable everyday underwear, the fibre composition is a useful point to check. Cotton underwear generally feels soft and is suitable for everyday wear. Elastane or spandex provides stretch and recovery, but a higher proportion of elastic fibres does not automatically mean the garment will feel more comfortable.

According to the product description, the Feelingirl light-shaping model consists of 60% recycled nylon, 28% nylon, 9% spandex and 3% cotton. The double layer around the tummy and elastic fabric around the bottom are specific construction features. The manufacturer describes the compression level as light shaping; this is not a medical function or a guarantee of a particular silhouette.

The product information for Calvin Klein models mentions a cotton-elastane blend, for example 95% cotton and 5% elastane in several 3-pack models. According to the product description, some models have an Infinity Bond seamless waistband and a moisture-wicking finish. These are brand claims, and the practical experience may vary from person to person.

3. Care, packaging and cost of use

A 3-pack of underwear can be useful for building a basic collection and makes the price per pair easier to assess. However, check exactly what you are receiving: a pack of three does not mean that all the models have the same rise, fabric or fit.

Also pay attention to care requirements:

  • Some Calvin Klein models are suitable for machine washing, often at a low temperature.
  • According to the product information, the Feelingirl shaping model must not be machine-washed, bleached or ironed; it should be air-dried.
  • According to the description, the Feelingirl bodysuit should be hand-washed and air-dried flat.

A product that needs to be hand-washed more often requires more time than standard cotton underwear. Take this into account when making your choice, especially if you are looking for several pieces for everyday wear.

Recommended choices for different user profiles

The selection below is based on verifiable details such as size range, material, cut, pack size and care instructions. The models are not identical: one is designed for light shaping, while another is intended for everyday comfort or a specific Brazilian cut.

Suitable for: Budget-conscious beginners
Calvin Klein 3 Pack Low Rise Trunks black 3XL

Calvin Klein 3 Pack Low Rise Trunks – black 3XL

Why it suits this profile: A 3-pack gives you three pairs straight away for your everyday wardrobe. The low-rise cut and black colour are ideal for shoppers looking for a simple men’s style.

How this product avoids the pitfall

The product information states the composition of 95% cotton and 5% elastane, along with a size chart showing waist measurements. This allows you to compare accurately rather than relying solely on the 3XL label.

Key benefit & advantages

Cotton-elastane blend, 3-pack, low-rise cut and available in 3XL.

Suitable for: Shoppers looking for premium quality
Calvin Klein Brazilian 3-pack black women’s 3XL

Calvin Klein Brazilian 3-pack UB1 black women’s 3XL

Why it suits this profile: This model is aimed at shoppers looking for women’s underwear with a Brazilian cut and a branded look, without having to put individual pairs together themselves.

How this product avoids the pitfall

The description explicitly states that the pack contains three pieces, with a Brazilian cut, cotton with elastane and machine-wash suitability. Check the care label and exact size before buying.

Key benefit & advantages

Brazilian briefs in a 3-pack, black colour and stretchy fabric for freedom of movement.

Suitable for: Specific use & intensive users
Feelingirl seamless high-waist shaping underwear 3XL 4XL

Feelingirl Seamless High-Waist Tummy Control 3XL/4XL

Why it suits this profile: Anyone looking for plus-size underwear with light shaping can consider this model. It is available in 3XL/4XL and features a high waist, a double tummy layer and stretchy fabric around the bottom.

How this product avoids the pitfall

The product description specifies “light shaping” and mentions the double layer around the tummy. So do not expect strong compression. Care is manual: do not machine-wash, bleach or iron.

Key benefit & advantages

Size 3XL/4XL, seamless design, high waist and a choice of nude, black and brown.

Suitable for: Anyone looking for targeted shaping
Feelingirl seamless shaping bodysuit for women XS S brown

Feelingirl Everyday Wear Seamless Shaping Bodysuit XS/S

Why it suits this profile: This bodysuit is designed for anyone who wants to smooth not only the tummy and waist but also the back and upper body under clothing. Adjustable straps and a hook fastening offer extra flexibility.

How this product avoids the pitfall

The description mentions targeted compression zones and an adjustable fastening. This makes it clearer where the garment provides shaping. It should be hand-washed and air-dried flat.

Key benefit & advantages

Seamless design, adjustable shoulder straps, hook fastening and size options up to 3XL/4XL within this product range.

Looking for more options?

We have put together a complete, up-to-date list of products that fully meet these strict selection criteria and the applicable European safety regulations.

Frequently asked questions about buying underwear online

How do I work out my size when buying underwear online?

Measure your waist and, if necessary, your hips with a flexible tape measure, without pulling it tight. Compare the result with the size chart on the product page. Also consider the rise and fit: a low-rise model and high-waist briefs sit in different places.

How long does underwear bought online last?

How long it lasts depends on the material, how often you wear it, washing and drying. Always follow the care label. Cotton styles that can be machine-washed are practical for everyday use. Shapewear with hand-wash and air-drying instructions requires more careful maintenance. Rotating between several sets can help reduce wear and tear.

Is a 3-pack of underwear better value?

Compare the total price with the price per pair and check what the pack contains. A 3-pack is practical when you want to wear the same cut and colour more often. Also pay attention to size availability, material and care requirements. A lower price per pair is less appealing if the fit does not suit how you plan to use it.