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

Buying underwear may seem simple, but an attractive offer doesn’t always tell you enough about comfort or how long it will last. A waistband that’s too tight, an unclear size guide or fabric that doesn’t suit how you’ll wear it could mean you stop wearing your purchase sooner than expected.

So keep an eye out for these three common pitfalls:

1. Choosing based only on the brand or price. Calvin Klein underwear, Reebok underwear and other well-known brands can use different fits and materials. The brand name is no substitute for checking the product specifications.
2. Choosing a multipack without working out the price per item. An underwear multipack is practical, but always check how many items it contains, what they’re made of and whether they’re all the same size and fit.
3. Assuming “soft” or “breathable” guarantees a particular result. These are often claims used in product descriptions. Instead, look at the exact fibre composition, waistband, leg length and care instructions.

Key things to consider when buying underwear

1. Check the fabric and stretch

For comfortable everyday underwear, the fabric composition is a good place to start. Cotton feels familiar and is widely used in men’s underwear, briefs and boxer shorts. A touch of elastane helps the garment move with you and keep its shape.

Seamless underwear is often made from synthetic fibres such as polyamide or nylon with elastane. It can be handy under close-fitting clothes, as there are fewer visible seams. Modal and lyocell are often chosen for their smooth feel. Always check the exact percentages on the product page and care label; terms such as “premium”, “antibacterial” or “skin-friendly” don’t in themselves guarantee a particular experience.

2. Choose a fit that suits how you’ll wear it

The right style depends on your clothes and activities:

• Briefs: compact and suitable when you want less fabric under your clothes.
• Boxer shorts and boxer briefs: offer more coverage for everyday wear, travel or exercise.
• Trunks: usually have shorter legs than boxer briefs, combining a close fit with extra coverage.
• Seamless underwear: a practical choice under thin or close-fitting clothes.
• Bikini briefs: a lower-cut style of women’s underwear. Check the leg opening and rise carefully.

A firm waistband should fit comfortably without digging into your skin. Also consider the placement of the seams, leg length and any support at the front. For sports, freedom of movement and an elasticated waistband matter more than appearance alone.

3. Compare the size, pack contents and care instructions

If you’re unsure, measure your waist or hips and compare them with the size guide for that specific product. A size S from one brand may not fit the same as a size S from another. Look out for terms such as “fitted”, “relaxed fit” and “regular waist”, too.

Care instructions affect how long underwear lasts. Some styles can go in the washing machine but shouldn’t be tumble-dried. Others need a low temperature or a delicates cycle. Always follow the care label. With a multipack, it’s worth checking that the colours, styles and size selection are what you need.

Recommended picks for different shoppers

Suitable for: Budget-conscious beginners

Utree Women's Modal Triangle Underwear 3-pack

Why it suits this shopper: A three-piece set is a practical way to build up a basic underwear collection. The product details list modal, a cotton gusset and sizes M, L and XL.

How this product avoids the pitfall

The product specifications state the number of items, fabric and available sizes, so you don’t have to rely on vague claims about comfort.

Key benefits & features

3-pack; modal as the main fabric; assorted colours in the set; several sizes to choose from.

Suitable for: Shoppers looking for premium quality

Calvin Klein Men's 3-Pack Boxer Briefs

Why it suits this shopper: These close-fitting boxer briefs are designed for everyday wear. According to the product details, they combine a lyocell blend with elastane and a supportive front panel.

How this product avoids the pitfall

The fabric composition and fit are clearly described. Before buying, check the available size and care advice for this specific style.

Key benefits & features

3-pack; lyocell, polyester and elastane; close fit; machine washable at 40 °C according to the product details.

Suitable for: Specific needs & active wearers

Reebok RBK Sports Trunks 5-pack

Why it suits this shopper: The product description focuses on everyday wear and sport. The flexible waistband and breathable design make it a good fit for an active wardrobe.

How this product avoids the pitfall

This style hasn’t been chosen on looks alone: the pack size, intended use and elasticated waistband are all clearly specified.

Key benefits & features

5-pack; suitable for everyday wear and sport according to the product details; elasticated waistband; machine washable.

Frequently asked questions about buying underwear

How often should you replace your underwear?

It depends on how often you wear and wash it, and on the condition of the fabric. Replace an item when the elastic loses its stretch, the seams come undone, the fabric thins or the fit changes permanently. A multipack makes it easier to rotate your underwear, so you don’t wear the same item as often.

Is cotton underwear suitable for sport?

Cotton underwear can be comfortable for everyday wear, but for sport, the fit, freedom of movement and how it handles moisture are what matter most. Compare the fabric composition and choose a style that doesn’t dig in or ride up. The word “sport” in a product description alone won’t tell you exactly how it will feel to wear.

How can you save money with an underwear multipack?

Work out the price per item and check that you’ll actually use all the colours and sizes. A larger pack isn’t automatically better value if some of it goes unworn. Check the care instructions, too: a style that needs careful washing may take more effort to look after than a machine-washable alternative.