GSM to oz/yd² Fabric Weight Converter
Instantly convert between grams per square meter (GSM) and ounces per square yard (oz/yd²). Whether you’re sourcing bulk bag fabric, comparing supplier specs, or verifying woven polypropylene weights, this tool gives you accurate results in one step.
How to Convert GSM to oz/yd²
The conversion formula is straightforward. Divide the GSM value by 33.906 to get oz/yd². To convert in the other direction, multiply oz/yd² by 33.906 to get GSM.
GSM ÷ 33.906 = oz/yd²
oz/yd² × 33.906 = GSM
Weight Ranges Reference
Light:
top panel & spouts, SWL under 1000 lbs
Medium:
SWL
1,500-2,500 lbs
Heavy:
SWL
2,800-3,500 lbs
Extra Heavy:
SWL 3,800+ lbs
GSM to oz/yd² Conversion Chart
For quick reference, here are common fabric weights and their equivalents. This covers the range most relevant to industrial textiles, woven polypropylene, and bulk bag fabrics.
| GSM | oz/yd² | Typical Use |
|---|---|---|
| 90 | 2.65 | Lightweight liners, dust covers |
| 120 | 3.54 | Light-duty bags, single-use packaging |
| 150 | 4.42 | Standard FIBC fabric, lightweight bulk bags |
| 180 | 5.31 | Mid-weight bulk bags, general industrial use |
| 200 | 5.90 | Standard woven PP for most bulk bag applications |
| 220 | 6.49 | Heavy-duty bulk bags, increased load capacity |
| 250 | 7.37 | Extra-heavy FIBC, chemical and mineral applications |
| 300 | 8.85 | Heavy industrial, high SWL requirements |
| 340 | 10.03 | Maximum-duty bulk bags, specialized applications |
| Sample #1 | Row 1, Content 1 | Row 1, Content 2 |
| Sample #2 | Row 2, Content 1 | Row 2, Content 2 |
| Sample #3 | Row 3, Content 1 | Row 3, Content 2 |
| GSM | oz/yd² | Typical Use |
|---|---|---|
| 90 | 2.65 | Lightweight liners, dust covers |
| 120 | 3.54 | Light-duty bags, single-use packaging |
| 150 | 4.42 | Standard FIBC fabric, lightweight bulk bags |
| 180 | 5.31 | Mid-weight bulk bags, general industrial use |
| 200 | 5.9 | Standard woven PP for most bulk bag applications |
| 220 | 6.49 | Heavy-duty bulk bags, increased load capacity |
| 250 | 7.37 | Extra-heavy FIBC, chemical and mineral applications |
| 300 | 8.85 | Heavy industrial, high SWL requirements |
| 340 | 10.03 | Maximum-duty bulk bags, specialized applications |
Most FIBC bulk bags use woven polypropylene fabric in the 150–250 GSM range. The right weight depends on the product being contained, the required Safe Working Load (SWL), and any regulatory or handling requirements specific to your industry.
What Is GSM?
GSM stands for grams per square meter. It measures how much one square meter of fabric weighs and is the international standard for specifying fabric weight. Higher GSM means a denser, heavier fabric. Lower GSM means lighter and more flexible.
In the United States, fabric weight is often quoted in oz/yd² (ounces per square yard) instead. International suppliers, particularly across Asia and Europe, almost always use GSM. If you’re sourcing bulk bags from overseas manufacturers and receiving specs in GSM while your internal documentation uses oz/yd², accurate conversion is essential for comparing quotes, verifying shipments, and maintaining spec compliance.
Why Fabric Weight Matters for Bulk Bags
In FIBC packaging, fabric weight directly affects bag performance. A heavier fabric generally means higher tensile strength, better UV resistance, and greater durability during handling and transport.
But heavier isn’t always better — overspecifying fabric weight adds material cost without improving performance for lighter-duty applications.
Here’s what fabric weight influences in a bulk bag context:
Safe Working Load (SWL)
Heavier fabric supports higher load ratings, but SWL also depends on construction style, seam strength, and lift loop design.
UV Resistance
Thicker fabric absorbs more UV stabilizer and degrades more slowly in outdoor storage. Critical for agricultural and building materials applications.
Moisture and Contamination Protection
Denser weaves reduce sift-through for fine powders and provide better barrier characteristics, though liners are still required for moisture-sensitive products.
Cost
Fabric is the single largest material cost in an FIBC. Getting the weight right means you’re not overpaying for unnecessary material and not underspecifying for your load.
At FlexSack, we manage 365+ different specifications in our inventory. Matching the right fabric weight to your application is one of the first conversations we have with every customer. If you’re unsure what GSM range fits your product, our Bag Features page breaks down how construction, fabric, and features work together.
FAQs
How do you convert GSM to oz/yd²?
Divide the GSM value by 33.906. For example, 200 GSM ÷ 33.906 = 5.90 oz/yd². To go the other direction, multiply oz/yd² by 33.906. The calculator at the top of this page handles both conversions instantly.
How many GSM is 1 oz/yd²?
One ounce per square yard equals approximately 33.91 GSM. This means a lightweight fabric at 3 oz/yd² would be roughly 102 GSM, while a heavier 10 oz/yd² fabric would be about 339 GSM.
What is a good GSM for bulk bags?
Most standard FIBC bulk bags use woven polypropylene in the 150–250 GSM range. Lighter-duty single-trip bags may use fabric as low as 120 GSM, while heavy-duty bags for minerals, chemicals, or high-SWL applications may go up to 300+ GSM. The right weight depends on your product, handling conditions, and any regulatory requirements. FlexSack’s team can help match fabric weight to your specific application.
Why do some suppliers quote fabric weight in GSM and others in oz/yd²?
GSM is the metric standard used internationally, particularly by manufacturers in Asia and Europe. oz/yd² is the imperial measurement still common in the United States. When sourcing from international suppliers, you’ll often receive specs in GSM that need to be compared against oz/yd² specs from domestic sources. Accurate conversion prevents ordering errors and ensures spec compliance across your supply chain.
What is the difference between fabric weight per square yard and per linear yard?
Ounces per square yard measures the weight of a fixed area (one yard by one yard) regardless of fabric width. Ounces per linear yard measures the weight of one running yard at whatever width the fabric happens to be. Two fabrics can have the same oz/yd² but very different oz/linear yard values if they’re different widths. When comparing fabric specs, always confirm which unit is being used. GSM and oz/yd² are both area-based measurements and are directly comparable.
Can I use this converter for any type of fabric?
Yes. The GSM-to-oz/yd² conversion is a mathematical constant (divide or multiply by 33.906) and applies to all fabric types: woven polypropylene, cotton, polyester, nylon, denim, canvas, and any other textile. The formula does not change based on material.
How do I measure the GSM of a fabric sample?
Cut a precise 10 cm × 10 cm square (100 cm²) and weigh it on a gram scale. Multiply the weight by 100 to get GSM. For example, if the square weighs 2.0 grams, the fabric is 200 GSM. For higher accuracy, use a larger sample (30 cm × 30 cm) and adjust the math accordingly. The formal test method is ASTM D3776.