Fung Fay sizing & fit notes
Updated October 16, 2026 — based on our white dress shirt operations experience
Short answer: Measure the dog, compare to the Amazon size chart for that ASIN, and prefer S / L / XXL when shopping our white dress shirt because those are the sizes we focus inventory on.
Which white shirt sizes do we focus on?
| Size | Weight band | ASIN | Note |
|---|---|---|---|
| S | 3.4–5.5 lb | B0FDGZ5XG8 | Preferred Amazon listing |
| L | 8.9–15.4 lb | B0FDGYL4Y4 | Usually in stock |
| XXL | 18.8–24.3 lb | B0FDGZ9JND | Often in stock |
M and XL appear on Amazon too; M has historically had higher return risk for us. Full chart on the white dress shirt page.
What did returns teach us?
On our white dress shirt, fit mismatches — especially garments that felt too small — drove a large share of returns. That is why this site pushes measuring and sizing up when between sizes, instead of only “buy the cute photo.”
How should you choose a size today?
- Measure chest, neck, and back (steps here).
- Open the size chart on the Amazon page for the exact ASIN.
- If any measurement sits at the top of a size range, take the larger size.
- Use Amazon’s return flow if needed — that is intentional with our FBA model.