Joybuy Insights

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

Underwear may seem like a simple purchase, but you quickly notice an incorrect size, unclear material composition or impractical fit. A low price per item means little if the waistband rolls, seams rub or the fabric loses its shape after just a few washes.

For online shoppers in the Netherlands, these are the main pitfalls to watch out for:

  • Relying only on the letter size: an M or L is not the same across every brand. Always check the waist and hip measurements in centimetres.
  • Confusing marketing claims with verifiable properties: terms such as “moisture-wicking”, “antibacterial” or “seamless” can mean different things from one product to another. Check the actual fabric, construction and care instructions.
  • Misjudging the number of items: a 3-pack of underwear or 5-pack of underwear can offer good value for everyday use, but also check the colours, available sizes and care requirements.

Which specifications matter when choosing underwear?

1. Fit and sizing

Choose the style based on your clothing and daily activities. Thongs and thongs provide little coverage and may be less visible under tight clothing. Briefs, hip briefs and bikini briefs offer more coverage. For men, boxers, trunks and classic briefs are common options.

When comparing products, check:

  • rise: low rise, mid-rise or regular waist;
  • leg opening: close-fitting or roomier;
  • support and shape of the front panel in men’s underwear;
  • hip and waist measurements in centimetres;
  • guidance such as “runs small” or “true to size”.

A product page that only provides a letter size does not give you enough information. This is particularly important when looking for plus-size underwear, such as 3XL or 4XL. Also check that the size is actually available for the style you have chosen. With some Calvin Klein products, the naming differs from the size chart shown.

2. Material and stretch

Cotton underwear is often chosen for its soft feel and breathability. Elastane provides stretch and helps the garment fit more closely. A composition such as 90% cotton and 10% elastane is more specific than a general claim about “stretch comfort”.

Modal generally feels smooth and supple. For a product made from modal, cotton and elastane, it is sensible to check the care label, as care requirements can vary depending on the composition. Also look at:

  • the percentage of cotton, modal, polyester and elastane;
  • the thickness and stretch of the fabric;
  • the finish of the waistband;
  • whether there are seams and hems;
  • whether the product can be tumble-dried.

Be cautious with “antibacterial” and similar claims. According to Utree’s product description, the gusset contains a so-called 10A antibacterial cotton component. This is a description provided by the brand or seller, not a general guarantee of how effective it is. Choose the product based on the listed materials, fit and care information.

3. Care and lifespan

Underwear is often washed several times a week. Practical care instructions are therefore more important than a prominent logo. Some styles can be machine-washed at 30 °C and must not be tumble-dried. Other products are suitable for low tumble-drying temperatures.

Always follow the care label. Washing at too high a temperature, bleach and a hot tumble dryer can damage elastic fibres. Over time, check that the waistband still fits properly, that the fabric is not becoming thin and that the seams remain intact. There is no fixed lifespan that applies to every material and frequency of wear.

Recommended underwear by user profile

Suitable for: Budget-conscious beginners
Reebok RBK SPORTS TRUNKS BAIRD

Reebok RBK SPORTS TRUNKS BAIRD – 5-pack

Why it suits this profile: A multipack containing five trunks is practical for everyday use and reduces the need to buy individual items.

How this product avoids the pitfall

The product information mentions an elasticated waistband, a 5-pack and machine washing. However, check the exact size and care instructions before buying.

Key benefit & advantages

Five items per pack; suitable for everyday use and physical activity according to the product description.

Suitable for: Shoppers looking for premium quality
Calvin Klein 3-Pack Slim Boxers

Calvin Klein 3-Pack Slim Boxers – Icon Cotton Stretch

Why it suits this profile: For anyone looking for Calvin Klein underwear with a close-fitting boxer cut, cotton stretch and three neutral colours.

How this product avoids the pitfall

The listing specifies a cotton-stretch blend, a seamless Infinity Bond waistband and washing at 30 °C. Size M is indicated as true to size.

Key benefit & advantages

3-pack in black, white and grey; slim fit; cotton and elastane according to the product information.

Suitable for: Specific use & intensive users
Utree women’s modal triangle underwear

Utree women’s modal triangle underwear – 3-pack

Why it suits this profile: Designed for anyone looking for a women’s style with generous coverage, stretchy fabric and multiple colours.

How this product avoids the pitfall

The description mentions a 3-pack, a 16 cm extended gusset and approximately 200% stretch. Check the style and size M, L or XL on the product page.

Key benefit & advantages

Modal fabric; high stretch; three colours per set according to the product information.

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 requirements.

Frequently asked questions about underwear

How do I choose the right underwear size?

Measure your waist and hips with a flexible tape measure, without pulling it tight. Compare the result with the size chart for the specific product. An M from one brand may fit differently from an M from another. Also read notes such as “runs small” and check whether the size chart is intended for women’s or men’s underwear.

How often should you replace your underwear?

It depends on how often you wear and wash it, as well as the material. Replace an item when the fabric becomes thin, the elastic stretches out, the seams come undone or the fit is no longer right. Rotating several pairs of briefs, thongs, boxers or bralettes means each item is worn less frequently.

Is a 3-pack or 5-pack of underwear better value?

A multipack can lower the price per item and is convenient for a regular washing routine. However, compare the total price, composition, colours and size availability. A 5-pack is not automatically better value if you rarely wear certain styles or colours. Also compare cotton underwear, seamless underwear and white underwear separately, as the features vary from one set to another.