Free Tools & Resources for Clothing Brands — The Toolbox by White Cotton

White Cotton provides six free, production-grade tools built from real factory experience. These tools help clothing brand founders prepare for manufacturing — from creating tech packs and size charts to calculating import duties and generating compliant care labels. No signup required.

Fabric Weight Converter — GSM to oz/yd² Calculator for Clothing Manufacturers

GSM (grams per square metre) and oz/yd² (ounces per square yard) are the two standard ways to measure fabric weight. European manufacturers use GSM; American suppliers use oz/yd². The conversion factor is 1 GSM = 0.02949 oz/yd². This free converter handles the maths instantly and shows you where your fabric sits on the weight scale.

Fabric weight determines how a garment feels, drapes, and performs. A lightweight t-shirt is typically 140–180 GSM (4.1–5.3 oz/yd²). A standard hoodie runs 320–400 GSM (9.4–11.8 oz/yd²). A heavyweight hoodie — like White Cotton's signature 1100 GSM double-layered construction — is one of the heaviest available from any European manufacturer.

Fabric Weight Recommendations by Garment Type

ResourcesFabric Weight Converter

Fabric Weight Converter

Convert between GSM and oz/yd² instantly. Find the ideal weight for every garment type and season.

9.4
Heavyweight320 GSM / 9.4 oz/yd²
100 GSM1100 GSM

Quick Reference

Common conversions

GSMoz/yd²CategoryTypical Use
1504.4UltralightSummer t-shirts
2005.9LightweightPremium t-shirts
2808.3MidweightLight sweatshirts
3209.4HeavyweightStandard hoodies
40011.8HeavyweightHeavyweight hoodies
48014.2HeavyweightPremium heavyweight
55016.2HeavyweightMax single-layer

Recommendations by Garment

Which weight to use

Recommended ranges based on our production experience. The ideal weight also depends on design, finish, and target market.

T-Shirts & Polos

Lightweight T-Shirt

140170160 GSM

Midweight T-Shirt

170210190 GSM

Heavyweight T-Shirt

210280240 GSM

Polo Shirt

180260220 GSM

Hoodies & Sweatshirts

Light Sweatshirt

240320280 GSM

Standard Hoodie

320400360 GSM

Heavyweight Hoodie

400500450 GSM

Ultra-heavy Hoodie

480550520 GSM

Pants & Shorts

Lightweight Shorts

180260220 GSM

Sweatshorts

260340300 GSM

Sweatpants

280400320 GSM

Heavy Sweatpants

380500420 GSM

Outerwear

Light Jacket

200320280 GSM

Longsleeve

180240200 GSM

Heavy Jacket

380550450 GSM

Varsity Jacket

400550480 GSM

FAQ

Frequently asked questions

GSM stands for grams per square meter — it measures fabric weight (density). A 180 GSM t-shirt is lightweight and breathable, while a 480 GSM hoodie is thick and structured. Higher GSM generally means heavier, warmer, and more premium-feeling fabric.

Need fabric swatches?

We send free fabric swatches so you can feel the weight and quality before you decide.

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