Size Guide

Find Your Perfect Fit

PREDICTION is built differently.

Sizing isn’t just waist — fit matters too.

Size Chart

Choose the leg fit that feels right for your thigh shape and comfort preference.

Size
Waist
Inseam
Leg Fit
MediumM
30–33"
8"
Standard / Slim
LargeL
33–36"
8"
Standard / Slim
X-LargeXL
36–39"
8"
Standard only*
Size
Waist
Inseam
Leg Fit
MediumM
30–33"
4"
Standard / Slim
LargeL
33–36"
4"
Standard / Slim
X-LargeXL
36–39"
4"
Standard only*
What's Slim?
Slim doesn't mean a smaller waist — only a slimmer thigh and leg opening fit.
Series Guide

Ad Astra or Ryder?

Both are built with PREDICTION utility, but each series is designed for a different carry style.

PREDICTION Ad Astra dual pocket boxer brief

Ad Astra

Maximum coverage and secure carry with dual-pocket utility.

Pockets Dual-pocket utility
Coverage Maximum coverage
Inseam 8"
Best For Travel, EDC, secure carry
PREDICTION Ryder single pocket boxer brief

Ryder

Lightweight everyday carry with a shorter, easy-moving profile.

Pockets Single-pocket carry
Coverage Light everyday carry
Inseam 4"
Best For Daily wear, lighter carry
PREDICTION Ad Astra vs Ryder comparison
Standard vs Slim

Built for different thigh profiles.

Most underwear brands only change the waist size.

PREDICTION also lets you choose how the leg fits.

Standard Fit

Relaxed, maximum comfort.

Designed for everyday comfort with a more relaxed feel around the thigh. Best if you prefer more room or have larger thighs.

Slim Fit

Closer, tailored fit.

Same waist size, but with a slimmer leg opening for a closer fit. Best if regular boxer briefs feel loose around your legs.

Which one should I choose?

Need max coverage?
Recommended
→ Ad Astra
Prefer shorter inseam?
Recommended
→ Ryder
Thigh over 21"
Best Fit
→ Standard
Thigh under 21"
Best Fit
→ Slim

Still not sure?

Start with your normal waist size. Choose Standard for more room around the thigh, or Slim for a closer, more tailored fit.

Learn about Standard vs Slim
Still unsure? Contact us — we’ll help you find your perfect fit.