Underwear Size Chart

Knowing your underwear size isn’t always easy and can lead to many purchases that quickly end up in the trash. From fit preferences to appearance, sometimes you really don’t know what looks and feels right until you try them on. Men’s and women’s underwear sizes aren’t universal and like a bra or T-shirt, can vary by brand or style. If you’re on the brink of giving up and going commando, we have the solution for you.

To help you find your dream fit every time, we created an underwear size chart with measuring tips and a fit guide to help you know your specific measurements no matter what brand or style.

How to Use the Underwear Size Chart

The first step in using our underwear size chart is knowing your body’s measurements. Knowing your body measurement is important for finding your perfect fit since sizes can vary. Women's and men's underwear sizes and fits are very different so we’ve broken down measurement tips to help you find the perfect size based on your body type and preferences. 

Grab your trusty measuring tape, and away we go!

Women’s Underwear Size Guide: How to Measure

When it comes to measuring women’s underwear sizes, there are a few tips to keep in mind to determine the right size.

Measuring at home before you shop can ensure you know your correct size and fit before going into the store or shopping online, and this applies to bras, underwear, and outerwear alike. You will get the most accurate measurement if you measure in your undergarments or tight-fitting clothing. When measuring, stand up straight and if possible, on an even surface. Put your feet together to measure and keep your body tall and relaxed. Ensure the tape measure is level all the way around your body and if you’re in between measurements, take note to size down! 

1. Measure Hip Size 

How do I measure my hip? Your hip measurement should include the fullest part of your hips and butt. Hold the start of the tape measure on one hip, wrap it around your butt and your other hip, and then return to where you started. If you prefer a looser fit, insert your forefinger between the tape and your hip to allow space. 

2. Measure Waist Size 

How do I measure my waist? Bend to the sides to reveal the natural crease in your waistline. Measure around your body along that line for your natural waist measurement.

3. Find Your Underwear Size 

Once you’ve located all your measurements, the hard part is over! Use our women’s underwear size chart below to locate your proper underwear size.

What if I’m Between Sizes?

If you’re in between sizes, we recommend sizing down. To hear what customers recommend around sizing, view reviews of specific products! 

Women’s Underwear Size Chart Tommy John uses letter sizing for our panties.
Sizes	Dress Size	Waist	Hip
XS	0-2	24 - 25”	34.5 - 35.5”
S	4-6	26 - 27”	36 - 37”
M	8-10	28 - 29”	38 - 39”
L	12-14	30 - 31”	40 - 41”
XL	16	32 - 33.5”	44.5 - 46”
XXL	18	37 - 38.5”	47 - 48.5”

Men’s Underwear Size Guide: How to Measure

When it comes to measuring men’s underwear size, there are a few differences for women. Since men’s underwear hits the waist level, measuring at the hips is unnecessary. 

1. Measure Waist Size 

How do I measure my natural waistline? Start at the top of your hip bone, then bring the tape measure all the way around your body, just above your belly button. Ensure it's not too tight and that your measure is level all the way around your body. Take a deep breath to ensure your waist measurement will fit comfortably.

2. Find Your Underwear Size 

If there's one thing on your body that should fit you like a glove, it's your underwear. Use our men’s underwear size chart below to locate your proper underwear size.

What if I’m Between Sizes?

A smaller size is best if you wear slimmer, more tailored shirts or pants. If you prefer a looser fit, size up.

Men's Underwear Size Chart Tommy John uses letter sizing for our underwear.
Size	Waist
S	28-30”
M	31-34”
L	35-38”
XL	39-42”
2XL	43-46”

How to Know If You Have The Right Underwear Size

By obsessing over every detail in our fabric, fit, and function, we have reinvented men's and women’s underwear to be the most comfortable underwear for women and men. That being said, it’s important to know how your underwear is supposed to fit and feel on your body.

Use our fit guides below to know how your underwear should fit properly. 

Women’s Underwear Sizes: Fit Guide 

1. Waistband: A waistband should be snug but not tight and lay flat on your waist.
2. Back/Butt: The fit should feel covered and comfortable. The fabric should stay in place, not ride up or sag.
3. Legs: Leg openings should be evenly arched on both legs, and the fabric should not bunch or twist.
4. Crotch: The crotch should fit naturally against your body and there shouldn’t be any excess fabric drooping down.

Women’s Underwear Sizes: Fit by Style + Type

Knowing your underwear size and how to convert your measurements in an underwear size chart is the best way to make sure you’re wearing a pair that will fit comfortably but what about different underwear styles and types? Explore our fit by style guide below.

1. Brief: Should give you full, soft coverage and support.
2. Thong: May be backless but it has your back (it’s so comfortable you won’t even feel it).
3. Cheeky: Has coverage that meets you in the middle- not too much fabric, but not too little—just a peek.
4. Boyshort: Gives you full coverage, plus hip coverage—pairs well with sleep, lounging, and flowy dresses in the summer. Should feel comfortable and not pinch in the crotch area (otherwise go up a size). Leg openings should be evenly arched on both legs.

Men’s Underwear Sizes: Fit Guide 

For men’s underwear, fabric, cut and fit can all impact the way a specific underwear size can look and feel. However there are tell-tale signs whether undies fit or not. 

1. Waistband: The waistband should lay snug but not tight on your waistline or leave any red marks. If the waistband cuts your body at all then you should go up a size.
2. Back/Butt: Fabric and fit should feel snug around your butt but not tuck or ride up. The fit should also not sag or else you should go down a size.
3. Legs: Edges should fit loosely around your legs and should not ride up. 
4. Crotch: For optimal comfort, fabric should fit close to the skin without being constricting or binding.

Men’s Underwear Sizes: Fit by Style + Type

From boxer briefs to trunks, all men's underwear styles offer differences in fit. Explore our fit by style and type guide below.

1. Boxer Brief: Provides the fullest amount of coverage and should lay snug on your body.
2. Relaxed Fit Boxer: Lays looser against the body for a more airy fit.
   Trunk: These boxers hit right at mid-thigh, creating a modern yet classy look for everyday wear.
3. Square Cut Boxer: These men’s briefs hug the body tight while giving off a contemporary appearance.
4. Brief: Offer minimal coverage while giving the most support.  

Underwear Size Chart: FAQs

How do you determine underwear size?

All you need is a soft tape measure! Bend to the sides to reveal the natural crease in your waistline. Wrap the tape measure around your waist where you typically wear your pants. This number, in inches, will give you your underwear size. For a more detailed breakdown, refer to our chart and step by step guide above.

What size underwear do I need?

After taking your measurements, refer to our men’s and women’s underwear size chart above!

Should you size up in underwear?

If your underwear squeezes your waist, your skin bulges or you get constant wedgies then you should probably size up. Also, a smaller size is best if you wear slimmer, more tailored shirts or pants. If you prefer a looser fit, size up.

Now that you are well equipped to find your perfect pair with our underwear size chart, branch out and find a superb underwear replacement that suits your style! Our focus on fit and function assures that whatever style you choose, you’ll feel comfortable and ready to take on the day. Our underwear doesn’t ride up or roll down, and we have a wedgie-free guarantee!