You can find the waist measurements for all of our underwear below.
| S | M | L | XL | XXL | |
| Waist | 28-30" | 31-34" | 34-36" | 36-40" | 42"-46" |
The waists on our underwear are designed to accommodate a range of sizes, but if you fall in between sizes and prefer a looser fit, the larger option may feel and fit better.
| Boxer Briefs | Trunks | Briefs |
| 18-Hour Jersey | 18-Hour Jersey | 18-Hour Jersey |
| Silver | Silver | AIRKNITX |
| AIRKNITX/AIRKNITX 8" | AIRKNITX | |
| 18-Hour Mesh |
| Boxers | Long Underwear | |
| 18-Hour Jersey Knit | Merino | |
| Woven Boxers | AIRKNITX Performance Tights |
18-Hour Jersey Boxer Briefs
The 18-Hour Jersey fabric fits close to the skin without being constricting.
The inseam of 18-Hour Jersey Boxer Briefs is 6" in all sizes, but since we use a gusset instead of a traditional inseam, the way we measure it may be different from other brands.
18-Hour Jersey Trunks
The 18-Hour Jersey fabric fits close to the skin without being constricting.
The inseam of 18-Hour Jersey Trunks is 3.75" in all sizes, but since we use a gusset instead of a traditional inseam, the way we measure it may be different from other brands.
18-Hour Jersey Briefs
The 18-Hour Jersey fabric fits close to the skin without being constricting.
18-Hour Knit Boxers
The 18-Hour Knit Boxers are made with the same fabric as our 18-Hour Jersey underwear, but in a knit fabrication for a looser fit. They have a button fly at the crotch and a covered waistband.
You can find the outseams of the 18-Hour Jersey Knit Boxers below. The outseam is the measurement along the outside of the leg, from the top of the waistband to the leg opening.
| S | M | L | XL | XXL | |
| Outseam | 13.75" | 14.5" | 15.25" | 16" | 16.75" |
Silver Boxer Briefs
The Silver fabric is mostly cotton, so while it's meant to fit close to the skin, it's not as close-fitting as our other fabrics.
The inseam of Silver Boxer Briefs is 6" in all sizes, but since we use a gusset instead of a traditional inseam, the way we measure it may be different from other brands.
Silver Trunks
The Silver fabric is mostly cotton, so while it's meant to fit close to the skin, it's not as close-fitting as our other fabrics.
The inseam of 18-Hour Jersey Trunks is 3.75" in all sizes, but since we use a gusset instead of a traditional inseam, the way we measure it may be different from other brands.
AIRKNITX/AIRKNITX 8" Boxer Briefs
The AIRKNITX fabric is a microfiber blend that's ideal for exercise. It's flyless and close-fitting for extra support, with four-way stretch that moves with you. Because of the elasticity, if you're on the lower end of a size range, you can comfortably size down.
The inseam of AIRKNITX Boxer Briefs is 5" in all sizes, but since we use a gusset instead of a traditional inseam, there may be some variation in the actual fit.
The AIRKNITX 8" Boxers Briefs are a modified version that adds 3" to the inseam to wick away moisture and prevent riding up while exercising.
AIRKNITX Trunks
The AIRKNITX fabric is a microfiber blend that's ideal for exercise. It's flyless and close-fitting for extra support, with four-way stretch that moves with you. Because of the elasticity, if you're on the lower end of a size range, you can comfortably size down.
The inseam of AIRKNITX Trunks is 3" in all sizes, but since we use a gusset instead of a traditional inseam, there may be some variation in the actual fit.
AIRKNITX Briefs
The AIRKNITX fabric is a microfiber blend that's ideal for exercise. It's flyless and close-fitting for extra support, with four-way stretch that moves with you. Because of the elasticity, if you're on the lower end of a size range, you can comfortably size down.
AIRKNITX Performance Tights
The AIRKNITX fabric is a microfiber blend that's ideal for exercise. It's flyless and close-fitting for extra support, with four-way stretch that moves with you.
Since the Performance Tights are full length, different sizes have different inseams. You can find the inseams below:
| S | M | L | XL | XXL | |
| Inseam | 28" | 28.5" | 29" | 29.5" | 30" |
18-Hour Mesh Boxer Briefs
The 18-Hour Mesh fabric is the same blend of materials as our 18-Hour Jersey, but in the pique weave fabrication that forms the mesh cool zones on our other underwear. It's flyless for extra support.
Woven Boxers
Our Woven Boxers are tailored to be less bulky but still looser-fitting.
You can find the outseams of the Woven Boxers below. The outseam is the measurement along the outside of the leg, from the top of the waistband to the leg opening.
| S | M | L | XL | XXL | |
| Outseam | 13.75" | 14.5" | 15.25" | 16" | 16.75" |
Merino Long Underwear
The Merino Long Underwear is made with a blend of Merino wool and a natural cellulose fiber that provides stretch and durability. The fabric fits close to the skin.
Since the Long Underwear are full length, different sizes have different inseams. You can find the inseams below:
| S | M | L | XL | XXL |
| 31.5" | 32" | 32.5" | 33" | 33.5" |