The Ends Per Inch (EPI) Calculator helps you calculate how many warp threads exist in one inch of woven fabric. This value directly reflects the density of warp yarns and affects the strength, flexibility, and texture of the final textile. The calculator serves weavers, textile engineers, fashion designers, and researchers in quality control and fabric production.
Knowing the EPI helps in selecting appropriate yarn tension, adjusting the loom, and planning patterns that need specific fabric tightness. It also helps ensure consistent quality across different batches of fabric or projects.
This calculator belongs to the Textile and Fabric Density Calculators category. It provides a fast and accurate way to assess how tightly woven your fabric is.
Formula of Ends Per Inch Calculator
The calculator uses a simple formula:
EPI = Number of Warp Ends / Width of the Fabric (in inches)
Detailed Breakdown:
- Number of Warp Ends
This is the total number of warp yarns arranged vertically on the loom during the weaving process. - Width of the Fabric
This refers to the horizontal span across which the warp ends are spread, measured in inches.
The formula results in the average number of warp threads per inch of fabric width.
Reference Table for Quick Use
| Warp Ends | Fabric Width (inches) | Ends Per Inch (EPI) |
|---|---|---|
| 600 | 60 | 10 |
| 800 | 40 | 20 |
| 900 | 45 | 20 |
| 1000 | 50 | 20 |
| 1200 | 60 | 20 |
Use this table as a quick guide for common warp setups without needing to run manual calculations.
Example of Ends Per Inch Calculator
Imagine a loom setup with 900 warp threads stretched over a fabric width of 45 inches.
EPI = 900 / 45 = 20
So, the fabric has an Ends Per Inch value of 20, indicating a moderately tight weave. This level of density is suitable for shirts, light upholstery, or scarves.
Most Common FAQs
A higher EPI means the fabric is denser and usually stronger but less flexible.
No. EPI is specific to weaving, not knitting. Knitting uses different measurements like gauge or stitches per inch.
Yes. You can use a pick glass or fabric counter to get an accurate warp end count per section before calculating EPI.