Joybuy Insights

Buying underwear online: how to choose comfortable, well-fitting underwear without a costly mistake

Buying underwear online may seem straightforward, but an attractive product photo doesn’t always tell you everything. You may not notice the wrong size, unclear fabric composition or a fit that shifts as you move until you’ve worn the item. With women’s underwear, men’s underwear, bras and sports bras in particular, small design differences can make a big difference to everyday comfort.

When shopping online, look out for these common pitfalls:

  • A size label without actual measurements: S, M and XL can vary between brands and styles. Check the waist, hip or bust measurements in the size chart.
  • Marketing claims without specifications: Words such as “breathable”, “shaping” or “extra supportive” don’t tell you much without details about the fabric, seams, band and fastening.
  • Choosing the wrong style for how you’ll use it: A thong worn under a fitted dress needs different features from cotton briefs for everyday wear. Sports underwear and disposable underwear for travelling also call for a different choice.

Which specifications should you check before ordering?

1. Fabric and stretch

Many people find cotton underwear comfortable and choose it for everyday wear. Cotton can be blended with elastane to help the garment move with you. Modal, nylon and polyamide are also commonly used in briefs, thongs, bras and seamless underwear.

Always check:

  • the fibre composition and percentages;
  • whether elastane has been added for stretch;
  • the care instructions;
  • whether the product is suitable for machine washing or hand washing.

A product description may, for example, refer to a soft or breathable fabric. Treat this as the brand’s description and check the fabric composition behind the claim. The Calvin Klein Relaxed Fit Trunk 3-Pack, for example, is listed as cotton with elastane. The product page also says it is machine washable and advises against tumble drying.

2. Fit, waistband and seams

A comfortable fit shouldn’t be too loose or dig in. For briefs and boxer shorts, check the rise, leg openings and whether there’s an elasticated waistband. Flat or minimal seams can be useful in seamless underwear under tight clothing, but getting the right size is still important.

For bras and sports bras, check for:

  • adjustable shoulder straps;
  • the width and stretch of the underband;
  • a fastening or pull-on design;
  • padded or unpadded cups;
  • the level of support stated in the product information.

Pay extra attention to styles that are described as coming up small. The Calvin Klein Unlined Bralette, for example, is listed as XS for EU sizes 32–34, and the product information says it may come up small. In this case, the size chart matters more than simply choosing your usual label.

3. Intended use and care

Multipacks and neutral colours are practical for everyday wear. A set of three briefs or boxer shorts makes it easier to change throughout the week. Disposable underwear can be handy for travelling, as you won’t need to wash it while you’re away. Be sure to check the size, packaging and information about single use.

For sport, choose a style that the product description says is suitable for the intensity of your activity. A running or fitness bra should stay securely in place, while a less structured design may be enough for yoga or light exercise. Claims about moisture-wicking, shock absorption or support come from the manufacturer, so check the fabric, underband and sizing in particular.

Our recommendations for different shoppers

Suitable for: Budget-conscious beginners
Calvin Klein Relaxed Fit Trunk 3P UB1 Black Men's L

Calvin Klein Relaxed Fit Trunk 3P. UB1 Black Men L

Why it suits this shopper: A multipack of three black trunks is a practical starting point for everyday wear, work and leisure.

How this product avoids the pitfall

The product information lists cotton, elastane, an elasticated waistband and a fitted cut. That means you can base your choice on specific features, rather than just the brand name.

Key benefits and features

Three pairs per pack, black, cotton with elastane, and machine washable according to the product information.

Suitable for: Shoppers looking for premium quality
Calvin Klein Push-Up T-Shirt Bra Beechwood 70 D

Calvin Klein Push-Up T-Shirt Bra - Seductive Comfort - Beechwood 70 D

Why it suits this shopper: This style is designed for anyone looking for a smooth bra to wear under T-shirts and fitted tops, with adjustable straps and a hook-and-eye fastening.

How this product avoids the pitfall

The product description lists smooth, seamless cups and size 70 D. Check the size and cup shape before ordering, rather than basing your choice on appearance alone.

Key benefits and features

Push-up style, smooth cups, adjustable shoulder straps and a neutral beechwood colour.

Suitable for: Specific needs and high-intensity use
High-intensity padded sports bra, black, XL

High-intensity padded sports bra - classic black - XL

Why it suits this shopper: This style is designed for running, fitness and other high-intensity workouts, where a firm underband and close fit are important.

How this product avoids the pitfall

The product description says the bra has padding, a wide underband and nylon-spandex fabric. These features are claims made by the brand, so also check the size and choose a style that doesn’t dig in.

Key benefits and features

Padding, a wide underband, a nylon-spandex blend and available in black in size XL.

Suitable for: Travellers and shoppers looking for convenience
YIJINCHAN men's disposable underwear, 3-pack, XXL

YIJINCHAN Men's Disposable Pure Cotton Underwear 3-Pack-XXL

Why it suits this shopper: Individually wrapped boxer shorts are handy for travelling, gym bags or situations where you can’t wash clothes straight away.

How this product avoids the pitfall

The product information lists 100% cotton, three pairs and a waist measurement range of 107–117 cm for XXL. This lets you compare the pack and size with your own needs before ordering.

Key benefits and features

Individually wrapped, three pairs of boxer shorts per set and a specific waist measurement range in the product information.

Looking for more options?

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

Frequently asked questions about buying underwear online

How do I find my size when ordering underwear online?

Measure your waist, hips or bust with a flexible tape measure, then compare the results with the size chart for the specific product. Don’t automatically choose the same size across every brand. For bras, check both the band size and cup size. If a style is listed as coming up small, take that into account when choosing your size.

How long does underwear usually last?

How long it lasts depends on the fabric, how often you wear it, and how you wash and dry it. Follow the care label, avoid unnecessarily high temperatures and don’t tumble dry items if this is advised against. Loose elastic, thinning fabric or lasting loss of shape are signs that it’s time to replace the garment.

Is a multipack of underwear better value?

A multipack can be practical and good value if you wear every item regularly. Compare the price per item and check whether the styles, sizes and fabrics are the same. A set is less worthwhile if some of the colours or fits don’t suit your clothes or everyday habits.