Thunderpants are made with our own blend of super stretchy organic cotton and spandex fabric. They are comfy, wedgie-proof, and there is no scratchy elastic that digs in. The ultimate comfy easy-fit undies!

The Original, Hipster, and Sky Rise styles all have the same fit through the leg and bum with varying height. The Hipster is low waisted, the Original sits around the navel, and the Sky Rise is high waisted.

The Boxer Brief is a mid-rise short leg trunk style. 

See the size guide below to help you choose the right size. If you happen to fall between the measurements, don’t panic! Use the hip measurement over the waist, and we recommend going up rather than down a size.....they will last longer and be more comfortable if not stretched too far. The thigh can get a wee bit tight if they are too small, but the waist should still fit just fine if you go up. 

The three styles are cut the same through the butt and legs, but the Hipster has a shorter rise than the Original and Sky Rise. The Hipster goes to about the low hip (thus the name Hipster!). The Original is 2” higher and usually hits below the belly button. The Sky Rise is our high waisted version that will hit at your natural waist, tapering in at the top.

The Hipster is more of a low rise style, the Original a higher rise - but not a high waist, and the Sky Rise a true high waisted undie! The Original is by far our more popular style and a little easier fit on most body types.

Constructed with our signature blend of Organic Cotton/Spandex fabric, our Bras and Cami are designed for the same easy comfort as our undies. 

The Bralette is a lower profile simple bra. It has a piece of elastic sewn in the binding below the bust for extra support. The single layer of fabric is very stretchy, so use the underbust measurements and the cup will stretch over your bust. If you get it too big the neckline can get too low, so if you feel like you’re in between sizes you may want to size down. It’s pretty true to size, but you can always email us with your measurements if you are unsure which size to order: info@thunderpantsusa.com.

The Longline Bra is a fuller coverage bra with a double layer of fabric in the front for extra support. These run true to size, and the fabric will stretch to accommodate a larger bust. You can size down for a little extra compression, but there is a piece of elastic rolled into the bottom hem and that could start to feel a little tight if you size down too far. They will ease as you wear them if it feels a bit tight when you first try it on.

The Cami is very stretchy and without a single piece of elastic in sight, can be ordered along fit preference. It has a wider strap to cover a bra, and is cut higher through the underarm and slightly wider through the hips for a snug yet modest fit. If you want it to fit snug and add a little compression, you may want to size down. 

Our Bike Shorts and Leggings are made with the same super stretchy Organic Cotton/Spandex fabric blend as our undies. 

All styles are all cut the same through the top and have different lengths. They all have a 4” wide double layer waistband that sits high on the waist and are fitted through the thigh and legs. Because our fabric is so stretchy, there is an element of preference in the sizing. Most people will be the same size in the Bike Short/Leggings as they are in the undies, but if you like a little extra support or tightness in your leggings, you may want to size down. Most of us in the office wear the same size undies as leggings/bike shorts, but some size down one or two sizes depending on fit preference. If you feel like you are in between sizes, then we suggest going down. The only risk in going down too far is the fabric stretching out more quickly or having a bit more transparency. 

Note that our Bike Short are different from the ones Thunderpants NZ sells. Ours are more fitted through the leg. 

The Bike Short comes down to mid thigh and inseam measures from 8.5” (SM) - 9” (3XL)

3/4 Legging Inseam measures from 21” (SM) - 21.5" (3XL)

Ankle Length Legging Inseam measures from 28" (SM) - 28.5” (3XL)

Extra Long Inseam measures from 32” (SM) - 32 1/2” (3XL)

This guide is based on many years of Thunderpants sales. As all children are different we suggest you go with your own intuition a little here. Thunderpants are very accommodating and tend to grow with your child so some children will wear their small undies well into the medium size range. Remember when your child outgrows the children's range they can move into the smaller adults sizes.

Our swimwear is made from a recycled nylon/lycra blend. This fabric is not nearly as stretchy as our organic cotton blend, so while we tried to keep the fit as similar as possible to the undies, there are some differences. 

Our Swimwear Top is a similar fit to our Bralette, but with more coverage. It is made with thinner binding around the ribcage and in the straps for a sleeker look. If you are in between sizes or small through the rib cage, you might want to size down. You don’t want the underbust binding to be too loose. 

Note the Classic Red Swimwear is fitting about 1/2 size LARGER compared to the other colors. 

Our swimwear is made from a recycled nylon/lycra blend. This fabric is not nearly as stretchy as our organic cotton blend, so while we tried to keep the fit as similar as possible to the undies, there are some differences. 

The Sky Rise is the most popular style and has a very cute vintage look to it. They fit very similar to the Sky Rise undies, but the waist is a tad looser (or you couldn’t get them on!). 

The Original Style fits a bit lower than our Original style undies, They are almost in between a Hipster and Original. If you like our Original undies you might consider Sky Rise swim bottoms unless you specifically want something lower. 

Most people will be the same size as the undies, but if you are in between sizes, you might opt to go down in the swim as opposed to up. You don’t want your swim too loose!