Quick answer
To choose the right underwear size, measure your natural waist and hip with a soft tape, then match those numbers to the brand's size chart rather than your jeans size. If you're between sizes, size up for comfort. Always check the product page for fabric and cut, because a stretchy trunk and a structured boxer brief can fit differently even in the same size.
Buying underwear online can feel like a gamble, especially when every brand seems to label sizes a little differently. The good news is that finding your true size takes about two minutes and a soft measuring tape. Once you know your waist and hip measurements, you can shop any style with confidence.
This guide walks you through measuring, reading a size chart, and testing the fit so you can avoid the most common mistakes. Whether you prefer a thong, trunk, or boxer brief, the same steps apply.
Step 1: Measure your waist and hips correctly
Stand relaxed and wrap a soft measuring tape around your natural waist, which is the narrowest part of your torso, usually just above your belly button. Keep the tape snug but not tight, and breathe normally. Write down the number in inches or centimeters. Then measure your hips at the fullest part of your seat, keeping the tape parallel to the floor.
If you don't have a soft tape, use a piece of string and then measure it against a ruler. For accuracy, measure twice. The numbers you get are your true measurements, and they're the only ones that matter for underwear sizing. Your jeans size is not a reliable substitute because denim brands cut differently.
- Common mistake: measuring over thick clothing or pulling the tape too tight, which gives a smaller number and leads to a too-snug fit.
Step 2: Match your measurements to the brand's size chart
Every brand publishes its own size chart, and HOM is no exception. Look for the size chart on the product page or in the site's help section. Find the row where your waist and hip measurements fall. If your waist points to one size and your hips point to another, choose the larger size for comfort, especially for styles with less stretch.
Pay attention to the fabric content. Materials like polyamide elastane offer four-way stretch and forgive small measurement differences, while pure cotton or structured fabrics have less give. The product description often tells you how the piece is meant to fit, so read it before you click add to cart.
- Checkpoint: if you're between sizes, always size up. Underwear that's too small will roll, dig, or ride up.
Step 3: Consider the cut and its intended fit
Different cuts sit differently on the body. A trunk is a shorter boxer brief that ends at the upper thigh, while a boxer brief offers more coverage. A thong or G-string has minimal back coverage and relies on a precise waist fit to stay in place. Swim shorts and loungewear may have their own sizing logic, so don't assume your underwear size transfers automatically.
For sports, look for styles designed with movement in mind. For example, the Mesh Boxer Briefs | White 400910-0003 are made from micro-ventilated polyamide that wicks sweat and dries fast, so they need to sit close without being restrictive. A looser fit would defeat the purpose of the fabric. Read the product facts for guidance on how each style is intended to fit.
Mesh Boxer Briefs | White 400910-0003
- Common mistake: buying the same size across all cuts. A thong and a boxer brief can fit differently even from the same brand.
Step 4: Test the fit when your order arrives
When your underwear arrives, try it on over clean skin and move around. Bend, sit, and walk. The waistband should stay flat without digging in or leaving red marks. The leg openings shouldn't pinch or ride up. If the fabric bunches at the front or back, the size is likely too large or the cut isn't right for your body shape.
A correct fit feels supportive but not tight. You should be able to slip a finger under the waistband. If you're unsure, check the brand's return policy before removing tags. Trying on over your existing underwear is a smart way to check size without compromising hygiene.
- Checkpoint: if you forget you're wearing them by mid-day, the fit is right.
Step 5: Adjust for fabric, shrinkage, and care
Natural fibers like cotton can shrink slightly after the first wash, while synthetic blends like polyamide elastane typically hold their shape. If you're buying cotton-rich underwear and you're between sizes, consider sizing up. Always check the care label: washing in hot water or tumble drying on high can shrink or damage elastic fibers.
To keep your underwear fitting well for longer, wash in cold or warm water and air dry when possible. Avoid fabric softener, which can break down elastic over time. Rotate your pairs so no single pair gets worn and washed constantly, which speeds up wear.
- Common mistake: assuming all fabrics shrink the same. Read the care instructions on the product page.
Your underwear sizing checklist
- Measure your waist and hips: Use a soft tape against bare skin or light clothing. Keep the tape level and snug, not tight. Write down both numbers. Checkpoint: measure twice to confirm accuracy.
- Read the brand's size chart: Find your measurements on the chart. If you fall between two sizes, choose the larger one. Checkpoint: don't rely on your jeans size.
- Check the fabric and cut: Stretchy polyamide elastane forgives small differences; cotton and structured fabrics have less give. Different cuts fit differently. Checkpoint: read the product description for fit notes.
- Try them on and move: The waistband should lie flat without digging. Leg openings shouldn't pinch or ride up. You should forget you're wearing them. Checkpoint: if you're between sizes, size up for comfort.
- Wash and care correctly: Wash in cold or warm water, avoid fabric softener, and air dry when possible to prevent shrinkage and elastic damage. Checkpoint: rotate your pairs to extend their life.
How HOM styles fit in practice
- Mesh Boxer Briefs | White 400910-0003: The MESH boxer briefs in very soft and supple micro-ventilated polyamide have been designed for sportsmen. The material in polyamide elastane gives these boxer briefs resistance to friction and a particularly soft touch and also allows it to dry very fast. The stretch and quick-dry fabric mean these boxer briefs should sit close to the body for wicking to work, so choose your measured size rather than sizing down for a tighter feel.
- Attack Trunk | Navy 401085-00RA: The ATTACK HOM trunks are a pair of short boxer briefs in polyamide elastane in heathered colors and neon details in a sportswear style which are adapted for sports. The microfiber material in polyamide elastane gives these trunks resistance to friction and a particularly soft touch and also allows it to dry very fast. The polyamide elastane blend stretches with movement, so if you're between sizes, the smaller size may still work for sport, but the larger size will feel more comfortable for all-day wear.
- Personal Allure G-String | Skin 463016-00DT: The PERSONAL ALLURE thong features fine vertical jacquard stripes in sheer tulle, a must-have from WOH for a discreet and invisible lingerie line. This play of semi-sheer stripes gives this thong an elegant and sensual look. A G-string relies on an accurate waist measurement to stay discreet and invisible under clothing. If the waistband is too loose, it will shift; too tight, and it will dig in.
Finding the right underwear size comes down to two measurements and a willingness to check the brand's chart. Measure your waist and hips, match them to the size chart, and size up when in doubt. With the right fit, you'll stay comfortable all day, whether you're at the gym or lounging at home.
