Size Guide

Thunderpants organic cotton and spandex fabric is super stretchy, comfy and easy-fit. There’s no nasty, scratchy elastic that digs in! They are the ultimate comfy, easy-fit undie.

The undie styles are designed to sit in the natural curves of the body and are cut with plenty of fabric to cover your bum. Our undies are naturally larger than other undies because of this. 

The size guide also correlates to our Swimwear, Leggings, and Bike Shorts. 

See the size guide below to help you choose the right size. If you happen to fall between the measurements, don’t panic, simply think about how you like to wear your clothes. If you prefer a looser feel, go larger and if you would rather feel snug in your clothes opt for the smaller size.

The sizes are standard US sizes:

Women's Hipster vs Original?

The two styles are exactly the same in every way except the hipster is shorter in the waist than the original. Those of us that have a bit of a tummy roll may wish to choose the original style as they cover the tummy.

The Original sits just below the belly button (higher waisted) and are great with tight or loose dresses (no seam showing at all) or with tights and leggings. The Hipster sits on your hips and are perfect for jeans!


Know your underwear size? Here's a conversion:

Women's Bralette: 

The bralettes are great for everyday wear for those of you who don't love wearing underwire and restricting bras. They're made with the same Organic Cotton as the underwear which makes them durable, stretch enough to cover your cup size, and have a great snap back to give some support. There is an elastic band around the under bust to hold everything up and in place. 

If you fall in between sizes, don't worry! We would recommend going down in size if you want more support and a snugger fit or going up in size if you would like less support and some extra breathing room. 

What about the kids?

Men's Fitted Boxer:

The Mens Fitted Boxer is sized small to extra large and is a closer fit than the Mens Original style. This is the option to choose if your like your undies be snug with a short leg. The front gusset is shaped and double layered for extra comfort, containment and help provide shapely lines.