Understanding fabric weight is essential for designers, manufacturers, and textile enthusiasts. Whether you are sourcing heavy denim or lightweight linen, converting between Ounces per Square Yard (oz/yd²) and Grams per Square Meter (GSM) is a daily necessity.
Our OZ to GSM Calculator provides instant, precise conversions to help you maintain quality control and material consistency across international standards.
Fabric Weight Converter
Why Convert OZ to GSM?
In the global textile industry, two main units define how heavy or thick a fabric is:
- Imperial (oz/yd²): Primarily used in the United States.
- Metric (GSM or g/m²): The standard unit for the rest of the world.
Because many suppliers list products in one unit while manufacturers require another, a precise conversion is vital for comparing fabric density accurately.
The OZ to GSM Conversion Formula
If you prefer to calculate the values manually, use the industry-standard conversion factor of 33.9057.
How to Convert OZ to GSM
To find the GSM, multiply the ounce value by 33.9057.
Formula: $oz/yd^2 \times 33.9057 = GSM$
Example: If you have a 6.5 oz denim, the calculation would be 6.5 × 33.9057 = 220.39 GSM.
How to Convert GSM to OZ
To find the ounces per square yard, divide the GSM value by 33.9057.
Formula: $GSM \div 33.9057 = oz/yd^2$
Example: A 300 GSM fleece would be 300 ÷ 33.9057 = 8.85 oz/yd².
Fabric Weight Reference Chart
Use this quick reference table for the most common fabric weights found in apparel and industrial textiles.
| Fabric Weight (oz/yd²) | Metric Weight (GSM) | Common Use Case |
| 4.0 oz | 135.6 GSM | Lightweight T-shirts, Linens |
| 5.3 oz | 179.7 GSM | Standard Jersey Cotton |
| 6.5 oz | 220.4 GSM | Heavyweight T-shirts / Polos |
| 8.0 oz | 271.2 GSM | Light Sweatshirts / Canvas bags |
| 10.0 oz | 339.1 GSM | Hoodies / Chinos |
| 12.0 oz | 406.9 GSM | Workwear Jackets / Denim |
| 14.0 oz | 474.7 GSM | Heavy Denim / Upholstery |
Frequently Asked Questions (FAQ)
1. What does GSM stand for in fabric?
GSM stands for Grams per Square Meter. It measures the density of the fabric. The higher the GSM, the heavier and usually thicker the fabric is.
2. Is a higher OZ always better for clothing?
Not necessarily. While a higher oz/yd² indicates a heavier fabric (like 14 oz denim), a lower oz/yd² is preferred for summer wear or breathable activewear (like 3 oz moisture-wicking polyester).
3. How do I convert 10 oz to GSM?
Simply multiply 10 by 33.9057. A 10 oz fabric is equal to approximately 339.06 GSM.
4. What is the standard weight for a quality T-shirt?
Most “premium” heavyweight T-shirts range between 6.0 oz (203 GSM) and 7.0 oz (237 GSM). Standard retail shirts are usually around 4.5 oz (152 GSM).
5. Does the weight of the fabric affect its durability?
Generally, higher weight (GSM) indicates more fibers per square inch, which often correlates with higher durability and warmth, though the fiber type (e.g., silk vs. cotton) also plays a major role.
Also see: Unit Converters