Why US import duty differs so much between cotton and polyester
As of 2026-10-23 (USITC HTS 2026 Revision 21), the general rate on knit cotton T-shirts is 16.5%, versus 32% for synthetic T-shirts such as polyester, a 15.5 percentage-point gap. Totals for China are 36.5% and 52%, respectively.
The same T-shirt shipment, different duty
Assume 1,000 units from China, with FOB and customs value both $5.00 per unit, for a shipment value of $5,000.00. Hold the other classification conditions constant and compare T-shirts & tank tops.
| Fiber | US HTS code | General rate | China total | Shipment duty | Duty per unit |
|---|---|---|---|---|---|
| Cotton | 6109.10.00 | 16.5% | 36.5% | $1,825.00 | $1.83 |
| Synthetic, including polyester | 6109.90.10 | 32% | 52% | $2,600.00 | $2.60 |
At the assumed equal price, synthetic costs $0.78 more in duty per unit, or $775.00 per shipment. Compare fabric costs and selling prices separately.
Differences use unrounded amounts, then round independently to cents; subtracting displayed amounts can differ slightly.
Where the cotton–synthetic gap is largest
Ranked by synthetic minus cotton general rate among 76 catalogue items with both fibers and purely ad-valorem rates. Ties at the cutoff are included. Items with a per-kilogram charge need a weight assumption and are excluded from this ranking.
| Item | Cotton | Synthetic | Gap (percentage points) |
|---|---|---|---|
| Bodysuits | 10.8% | 32% | 21.2 |
| Men's woven swimwear | 7.5% | 27.8% | 20.3 |
| Men's knit suits | 9.4% | 28.2% | 18.8 |
| Women's overcoats, long coats & raincoats | 8.9% | 27.7% | 18.8 |
| Women's woven jackets, windbreakers & anoraks | 8.9% | 27.7% | 18.8 |
| Men's overcoats, long coats & raincoats | 9.4% | 27.7% | 18.3 |
| Men's woven jackets, windbreakers & anoraks | 9.4% | 27.7% | 18.3 |
| Men's woven blazers & suit jackets | 9.4% | 27.3% | 17.9 |
| Women's woven blazers & suit jackets | 9.4% | 27.3% | 17.9 |
Why rates differ, and how to treat blends
The US schedule assigns different HTS subheadings and general rates to different fibers. Here cotton starts at 16.5%, adds 7.5% + 12.5%, and totals 36.5%. An HS classification needs construction, fiber and garment details, not just “T-shirt”.
Ordinary blends generally follow the fiber that predominates by weight over each other fiber; it need not exceed half of the total. Synthetic here includes polyester; artificial fibers such as viscose are a separate category. Equal weights, fiber-grouping rules and special products require the tariff notes rather than this shortcut.
Sources and data date
StoreCalc generated this guide on 2026-10-23 using USITC HTS 2026 Revision 21 and its calculators.
Rates come from the relevant HTS subheadings and chapter 99; amounts use the duty calculator's shipment formula. Classification depends on the actual product.
USITC Harmonized Tariff Schedule