Men’s Underwear Fit Guide
Trunks, Boxer Briefs, Briefs & Woven Boxers Explained
Not sure which underwear style is right for you? Our men’s underwear fit guide explains the difference between trunks, boxer briefs, briefs and woven boxers, with practical fit advice and a general size guide to help you choose with confidence.
A practical customer guide for choosing the right style, fit and size.
Trunks
Trunks are one of the most popular modern men’s underwear styles. They usually have a shorter leg than boxer briefs and a fitted, square-cut shape that sits close to the body.
How trunks fit
Trunks normally sit low to mid-rise on the waist and offer a close, supportive fit. The shorter leg makes them a good choice under jeans, chinos, shorts and slim-fit trousers.
Best for
- Everyday wear
- Slim or regular trousers
- Men who want support without a long leg
- Modern designer underwear styling
- Warmer weather or summer dressing
Fit feel
- Supportive
- Streamlined
- Shorter on the thigh
- Less fabric than boxer briefs
- More coverage than briefs
Because trunks have a shorter leg, some men may find they ride up slightly depending on body shape, thigh size and fabric stretch. If you prefer more thigh coverage, boxer briefs may be a better option.
Boxer Briefs
Boxer briefs are fitted like trunks but usually have a longer leg. They offer more coverage down the thigh while keeping a supportive, close-to-body fit.
How boxer briefs fit
Boxer briefs sit close against the body and extend further down the thigh than trunks. They are designed to give support, coverage and a smooth fit under clothing.
Best for
- Everyday comfort
- Workwear and longer days
- Gym, walking and active use
- Men who prefer more thigh coverage
- Wearing under jeans, trousers and joggers
Fit feel
- Supportive
- Secure
- Longer leg coverage
- Smooth under trousers
- Good for movement
Boxer briefs can feel warmer than trunks because they use more fabric. For summer or travel, look for breathable cotton stretch, modal, bamboo, lyocell or performance fabrics.
Briefs
Briefs offer a classic supportive fit with no leg coverage. They sit neatly around the waist and hips and are designed for support, simplicity and freedom of movement.
How briefs fit
Briefs provide support around the front and seat without fabric extending down the thigh. They usually feel lighter and cooler than trunks or boxer briefs.
Best for
- Men who prefer maximum support
- Warmer weather
- Wearing under slim trousers
- Sport and movement
- Men who do not like fabric on the thigh
Fit feel
- Supportive
- Lightweight
- No leg coverage
- Secure around the seat
- Traditional underwear feel
Briefs offer less coverage than trunks and boxer briefs. Some men prefer them for comfort and support, while others prefer the more modern look of trunks or boxer briefs.
Woven Boxers
Woven boxers are looser-fitting underwear made from non-stretch or lightly structured cotton fabric. They are designed for relaxed comfort rather than close support.
How woven boxers fit
Woven boxers sit away from the body with a looser shape. They usually have a button fly or open fly and feel airy, relaxed and traditional.
Best for
- Relaxed everyday wear
- Sleeping and lounging
- Men who dislike tight underwear
- Looser trousers
- Classic boxer short comfort
Fit feel
- Loose
- Breathable
- Traditional
- Less supportive
- Relaxed around the thigh
Woven boxers are not as supportive as trunks, boxer briefs or briefs. They may bunch under slim jeans or fitted trousers, so they are often better with looser clothing.
Quick Underwear Style Comparison
| Style | Fit | Leg Length | Support | Best Use |
|---|---|---|---|---|
| Trunks | Fitted | Short | High | Everyday, slim trousers, modern fit |
| Boxer Briefs | Fitted | Medium to long | High | Everyday, work, gym, longer coverage |
| Briefs | Fitted | No leg | High | Support, warm weather, slim clothing |
| Woven Boxers | Loose | Medium | Low to medium | Lounging, sleeping, relaxed comfort |
General Men’s Underwear Size Guide
This size guide is a rough guide only. Every brand can fit differently, and some fabrics stretch more than others. Always check the individual product size guide before ordering.
| Size | Approx. UK Waist | Approx. Waist CM |
|---|---|---|
| Small | 28–30 in | 71–76 cm |
| Medium | 31–33 in | 79–84 cm |
| Large | 34–36 in | 86–91 cm |
| X-Large | 37–39 in | 94–99 cm |
| XX-Large | 40–42 in | 102–107 cm |
How to Measure Your Waist
Use a soft tape measure around the area where your underwear waistband normally sits. Keep the tape flat, comfortable and not too tight.
If you are between two sizes, choose based on your preferred fit. Choose the smaller size for a closer, more supportive fit. Choose the larger size for more comfort and room.
Fabric & Fit Notes
- Cotton stretch underwear gives a familiar everyday feel with added stretch.
- Modal and lyocell often feel softer and smoother against the skin.
- Bamboo fabrics can feel breathable and naturally soft.
- Performance fabrics are useful for gym, travel and active days.
- Microfibre styles often feel lightweight, smooth and quick-drying.
Which Underwear Style Should I Choose?
- Choose trunks if you want a modern everyday fit with a shorter leg.
- Choose boxer briefs if you want more thigh coverage and a secure fit.
- Choose briefs if you want maximum support with no leg fabric.
- Choose woven boxers if you want a looser, relaxed traditional fit.
Continue Shopping
Ready to choose your preferred style? Explore our most popular men’s underwear collections below.
Final Advice
The best underwear depends on your body shape, outfit and personal comfort. Many men keep more than one style in rotation: trunks for everyday wear, boxer briefs for longer coverage, briefs for support, and woven boxers for relaxed comfort.
