Finding Your Perfect Fit

At TomboyX we care about how our products fit you. In fact, that’s our main thing. Before a product goes live on the website it can spend up to a year in development. Why? Because we want you to feel comfortable and confident in everything you buy from us. That, and the fact that we don’t half-ass anything. At TomboyX we believe it’s whole-ass or nothing.

Which is why we are rolling a new Fit Guide to help you find the perfect product for you. Consider this post your definitive guide to everything TomboyX. From fit to fabric we want to help you find something that makes you feel both comfortable and confident.


Let’s start with the most important thing: the fit. We fit-test our products in every shape and every size. What that actually looks like is a team of designers testing our products across hundreds of bodies, sending them out for hours upon hours of real-life wear testing, and endlessly tweaking designs to improve our fit.

Underwear -

Below you’ll find our brand new fit-guide comparison chart which shows the cut of our Thong, Bikini, and Iconic Briefs—including where the waistband and hem will sit.

Underwear Fit Guide

Boxer Briefs -

Below you’ll find our brand new fit-guide comparison chart which shows the cut of our Boy Shorts, 4.5” Trunks, 6” Fly, and 9” Boxer Briefs—including where the waistband and hem will sit.

Boxer Brief Fit Guide

Bras -

With four unique cuts of bras we think you’ll be able to find one that fits you just right. Our fit-guide shows how each bra is cut both front and back, as well as how much coverage you can expect out of each style.

Bras Fit Guide

Bra Fit Guide 2

Sleep and Loungewear Tops -

Our sleepwear and French Terry tops are all cut to a Regular Fit. Though if you would like a more relaxed, traditional hoodie fit with our French Terry collection we suggest sizing up.

Tops Fit Guide

Sleep and Loungewear Bottoms -

Our Long Johns are cut the same way all our underwear are with a Body Contouring Fit. The rest of our sleepwear and lounge bottoms including pajama pants and joggers are cut with a Regular Fit. Our MicroModal pajama pants sit with a Regular Fit through the hips and thighs, but expand to a looser fit around the calves and ankles.

Bottoms fit guide


All the fabrics we use at TomboyX must meet our exacting standards. This includes working with certified mills and factories, conducting formal lab testing, fit approvals, and real-life wear testing. We scour the world for fabrics that are eco-friendly, soft, and retain their stretch, shape, and comfort over multiple wears and wash cycles. The whole point is to design something that you want to have in your underwear drawer—something you can count on and feeling good about wearing.

Our Waistband -

Okay, our waistband is not technically a fabric but it is the signature touch that makes all our products feel silky-comfortable against your skin. We spend as much or more time developing our elastics as we spend on fabrics. We make our waistband with a specific nylon yarn which is reliable and consistent across all uses. We take the extra time to make sure the white is white, the black is black, and the logo is perfect.

Cotton-Spandex -

Made from quality yarns, our cotton-spandex fits a broad range of sizes and shapes, has a long lifespan, and is designed to combat riding up, slipping down, or chafe.

MicroModal -

This fabric is excellent for all body shapes because it stretches to meet you and won’t work against you. It is a lighter, more luxurious fabric making it a great companion to cotton-spandex. MircoModal is good for those folx who are on the upper range of our size offering because it has more stretch than our cotton-spandex and can accommodate a larger size.

Traveler -

A quick-drying, durable, and light fabric built with antibacterial and antimicrobial technology. This fabric is silky to the touch and is a great option for those with an active lifestyle.

First Line -

The solution to insure your confidence and comfort during light periods and incontinence. First Line looks and feels like regular TomboyX underwear but with fabric that is treated to be water-repellent. The lining is also antimicrobial and multi-layered for all day dryness.

Swim -

Our swim fabrics are antibacterial, wicking, resists pilling, and are UPF 50. In addition to that, we have a specialized anti-odor finish made of crab and shrimp shells that ensures an eco and human-friendly life of the product.

French Terry -

As durable and enduring this 100% cotton fabric has a soft, cozy feeling. This fabric will be your go-to for years to come.


That’s fine. We know that buying underwear online can be a daunting process. If you’re still unsure of what size, cut or fabric will work best for you please reach out to our customer service team. These special folks handle every question, comment, and review that comes into TomboyX HQ and they would love to chat with you about underwear. Seriously. You can reach them at