Men's Vest & Underwear Size Guide (S to XXL, in Inches)
A simple size chart for men's vests, briefs and trunks in inches, how to measure at home, and what to do between sizes.
By the SFIVA team · 26 September 2026
The wrong size is the most common reason innerwear feels uncomfortable. Two minutes with a measuring tape solves it.
How to measure
- Chest (for vests): wrap the tape around the fullest part of your chest, under the arms, keeping it level.
- Waist (for briefs and trunks): measure where your trousers usually sit, not your natural waist.
- Breathe normally and keep the tape snug but not tight.
SFIVA vest sizes
- S — chest 34–36"
- M — chest 36–38"
- L — chest 38–40"
- XL — chest 40–42"
- XXL — chest 42–44"
SFIVA underwear sizes
- S — waist 28–30"
- M — waist 30–32"
- L — waist 32–34"
- XL — waist 34–36"
- XXL — waist 36–38"
Between two sizes?
For vests, size up if you like a relaxed fit or wear it under a fitted shirt in summer. For underwear, choose by your trouser waist size — a waistband that is too tight rolls, one too loose slips.
Still unsure?
Message us on WhatsApp with your trouser size and height and we will recommend a size. And if it does not fit, unopened items can be returned within 14 days.
