You want a t-shirt that's actually made from cotton. Not "cotton-feel." Not "cotton-blend." Not 60% cotton with 40% polyester hiding in the small print. Actual, 100% cotton.
Good news: t-shirts are one of the easiest categories to find natural fibres. We analysed 1,487 t-shirts across major retailers using Fibr, and the numbers are genuinely encouraging.
Why 100% Cotton Matters for T-Shirts
T-shirts sit against your skin all day. The fabric isn't just a detail — it's the entire experience of wearing the garment. Here's why cotton wins:
- Breathability: Cotton fibres are naturally porous. Air moves through, heat escapes, your body can regulate its temperature the way it's meant to.
- Odour resistance: Bacteria — the actual cause of body odour — thrive on polyester and struggle on cotton. A cotton tee stays fresh dramatically longer than a synthetic one.
- Feel: There's a reason "cotton-soft" is a selling point. Cotton feels good against skin from day one and gets softer with every wash.
- No pilling: Those little fabric bobbles that make a t-shirt look worn out after three washes? That's a polyester problem. Pure cotton pills minimally, if at all.
The Good News: T-Shirts Are the Easy Win
Across all the categories we track, t-shirts consistently have the highest natural fibre content. Dresses average much lower. Sweaters are often loaded with acrylic. But t-shirts? Retailers actually use cotton for these.
That 87.3% average means the typical t-shirt you pick up is mostly cotton. But "mostly" isn't "100%." If you want pure cotton, you need to know where to look — and what to avoid.
Where to Find Cotton T-Shirts: Brand by Brand
We broke down t-shirt fibre composition by retailer. Here's what we found:
| Brand | Avg Natural Fibre | T-Shirts Analysed | Verdict |
|---|---|---|---|
| Zara | 89.8% | 365 | Strong — large range, high cotton content |
| Reformation | 88.9% | 9 | Very high — but limited t-shirt range |
| Bershka | 87.1% | 1,021 | Reliable — huge selection, solid natural content |
| Mango | 81.6% | 88 | Decent — but check individual products carefully |
Zara: Best Combination of Range and Quality
Zara's t-shirt range averages 89.8% natural fibre across 365 products. That's a large selection with consistently high cotton content. You'll still find blends in the mix, but the odds of grabbing a pure cotton tee at Zara are very good.
Bershka: The Volume Play
With 1,021 t-shirts analysed, Bershka has the biggest range by far. The 87.1% average natural fibre content means most of their tees are cotton-dominant. When you're shopping 1,000+ options, a quick fibre check helps you filter straight to the 100% cotton ones.
Reformation: High Quality, Small Range
Reformation's 88.9% average is impressive, but it's based on just 9 t-shirts. If they have what you want, the fibre content is likely excellent. But don't expect a huge selection to browse.
Mango: Worth Checking, but Verify
Mango's t-shirts come in at 81.6% average natural fibre — still good, but notably lower than Zara or Bershka. This means more blends in the mix. Individual product checking matters more here.
What to Watch Out For
Retailers are not always straightforward about fabric content. Here are the traps:
- "Cotton Feel" or "Cotton Touch": This is marketing language for a polyester-heavy blend that's been treated to feel soft. It is not cotton. Check the actual composition.
- "Cotton Rich": Usually means 50-70% cotton, 30-50% polyester. Better than full synthetic, but not what you're after if you want 100% cotton.
- "Organic" without a percentage: "Organic cotton" is great, but a shirt can be "made with organic cotton" and still be 40% polyester. The word "organic" describes how the cotton was grown, not how much of it is in the garment.
- Elastane additions: Many otherwise-cotton tees contain 2-5% elastane (spandex) for stretch. This is a small amount and keeps the shirt from losing its shape. Whether this bothers you is personal — it's not polyester, and 95% cotton / 5% elastane is a completely different thing from 60/40 cotton/poly.
The rule: Look for "100% Cotton" in the fabric composition, not in the marketing copy. If the composition section says anything else, it's not 100% cotton — no matter what the product title claims.
How to Verify Before You Buy
Hunting for fabric composition on product pages is tedious. It's usually buried in an accordion section, sometimes labelled "Composition," sometimes "Materials," sometimes "Care & Fabric." Some retailers don't surface it until you click three times.
With Fibr installed, shopping for 100% cotton t-shirts becomes trivially easy. Open a retailer, browse t-shirts, and the fibre content is right there on every product image. No investigation required.
The Bottom Line
T-shirts are the one category where natural fibres are genuinely easy to find. With an 87.3% average natural fibre content across nearly 1,500 products, the deck is already stacked in your favour. Zara and Bershka offer the best combination of high cotton content and large ranges. Just make sure you're reading the actual fabric composition — not the marketing — and you'll find what you're looking for.