Size chart & fit guide
Diamond MMA Size Chart
Size every Diamond MMA jock, short and brief by your waist, measured just above the hips. Not your pant size. Athletic cups come in Youth and Adult, and most athletes move to the adult cup around ages 14 to 15.
Start here
How do I measure for a jock or compression short?
It takes about a minute with a soft tape measure.
Find your natural waist
It's just above your hip bones, usually a little above your belly button.
Measure around
Wrap the tape around your body, level and snug, but not tight. Don't go by your pant size.
Match the chart
Find your waist in the chart for your product. Weight ranges are there to help if you're on the line.
Athletic cups
What size athletic cup do I need?
Our athletic cup comes in two sizes. Both use the same polycarbonate shell and soft rubber elastomer rim. Pick the one that covers fully without pinching at the edges.
| Cup | Length | Width | Depth |
|---|---|---|---|
| Youth | 5.5" | 3" | 2" |
| Adult | 6.75" | 4" | 2.25" |
When to move up: most athletes move from the youth cup to the adult cup around ages 14 to 15, depending on body type. If the youth cup no longer covers everything, it's time.

Adult
Quad Strap Jock & Compression Jock Short size chart
Built for a snug, supportive fit. Adult sizes have a drawstring waistband.
| Size | Waist | Weight (approx.) |
|---|---|---|
| Small | 28–30" | 120–150 lb |
| Medium | 30–32" | 140–170 lb |
| Large | 32–34" | 160–190 lb |
| X Large | 34–36" | 180–220 lb |
| 2XL | 36–40" | 210–260 lb |
| 3XL | 41–44" | 250–300 lb |
Fits: Quad Strap Jock System · Quad Strap Jock · Compression Jock Short System · Compression Jock Shorts
Youth
Youth jock & compression short size chart
Youth sizes don't have a drawstring, so measure carefully. Outgrown Youth X Large? Move to adult Small.
| Size | Age (approx.) | Waist |
|---|---|---|
| Youth Medium | 8–10 | 22–24" |
| Youth Large | 10–12 | 24–26" |
| Youth X Large | 12–14 | 26–29" |
Fits: Youth Quad Strap Jock System · Youth Compression Jock & Athletic Cup System · Youth Compression Jock Short System | White
Hockey
Hockey jock short, garter & jock pant size chart
Our hockey line runs Small to 2XL. Between sizes, or thicker in the thighs or seat? Go up a size.
| Size | Waist | Weight (approx.) |
|---|---|---|
| Small | 28–30" | 120–150 lb |
| Medium | 30–32" | 140–170 lb |
| Large | 32–34" | 160–190 lb |
| X Large | 34–36" | 180–220 lb |
| 2XL | 36–40" | 210–260 lb |
Fits: 3 in 1 Hockey Garter Belt · Hockey Jock Short System · Hockey Jock Short · Cut-Resistant Hockey Jock Short System · Cut-Resistant Hockey Jock Pant System
Performance Short
Performance Short size chart
The Performance Short runs on its own chart, Small to X Large, for both the built-in jock and built-in brief versions. The waistband has a drawstring.
| Size | Waist | Weight (approx.) |
|---|---|---|
| Small | 28–30" | 140–170 lb |
| Medium | 31–33" | 170–200 lb |
| Large | 34–36" | 200–230 lb |
| X Large | 37–40" | 230–270 lb |
Fits: Performance Short With Built-In Jock System · Performance Short With Built-In Jock · Performance Short With Built In Brief
Briefs
Compression Brief & Sports Boxer Brief size chart
Both briefs share one chart. They're made for support on days you don't need a cup. Size down for more compression, or size up for a more relaxed everyday fit.
| Size | Waist | Weight (approx.) |
|---|---|---|
| Small | 28–30" | 130–155 lb |
| Medium | 31–33" | 155–185 lb |
| Large | 34–36" | 185–215 lb |
| X Large | 37–40" | 215–250 lb |
| 2XL | 41–44" | 250–290 lb |
Fits: Compression Brief · Sports Boxer Brief
Fit tips
Between sizes?
Bigger thighs or glutes
Size up. The quad straps and leg openings will sit more comfortably.
Leaner build
Take the smaller size for a closer fit that holds the cup tighter.
Wrong size?
Exchanges are free on every order. Start one in the returns portal.
Apparel
Rash guard & T-shirt size charts
Questions
Sizing questions
How should an athletic cup fit?
It should cover everything, sit flat against your body and stay put when you run or squat. If it gaps at the edges or pinches, try the other size.
Should I go by my pant size?
No. Measure around your natural waist, just above the hips. Pant sizes vary by brand and usually sit lower on the body.
When should a youth athlete move to the adult cup?
Most athletes move from the youth cup to the adult cup around ages 14 to 15, depending on body type. If the youth cup no longer covers everything, it's time to size up.
Can I get a youth cup with an adult jock?
Yes. Our adult Systems let you choose the adult or youth cup, which works well for teens and smaller-framed athletes.
What if I'm between sizes?
Athletes with bigger thighs or glutes usually size up. Leaner builds may like the smaller size for a closer fit. Exchanges are free if you need to swap.
What if it doesn't fit?
Exchanges are free on every order. You can also return it within 30 days of delivery. Start through our returns portal.
Still not sure?
Answer a few questions and we'll match you to the right jock, cup and size for your sport. Or email info@diamondmma.com and our team will help.
WE BACK EVERY SALE WITH A 100% SATISFACTION GUARANTEE





