1. What is Pattern Size Calculation?

Pattern size calculation is essential for creating well-fitting bags. It accounts for both the desired finished size and the necessary seam allowance to ensure proper construction.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• Desired Size — The final dimensions you want your bag to be (cm)
• Seam Allowance — Extra fabric needed for seams (typically 0.5-1.5 cm)

Explanation: The pattern must be larger than the finished size to account for the fabric that will be taken up in the seams.

3. Importance of Accurate Pattern Sizing

Details: Proper pattern sizing ensures your finished bag will be the correct dimensions. Too small and the bag won't hold what you need; too large and it may lose its intended shape.

4. Using the Calculator

Tips: Enter your desired finished size in centimeters and your preferred seam allowance. Standard seam allowances are typically 1 cm for bags, but this may vary based on your project.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical seam allowance for bags?
A: Most bag patterns use 1 cm seam allowance, but heavier fabrics may require more (1.5 cm) while delicate fabrics may use less (0.5 cm).

Q2: Should I add seam allowance to all dimensions?
A: Yes, you should add seam allowance to each edge that will be sewn. For a rectangular bag, this means adding twice the seam allowance to both length and width.

Q3: How does this work for curved seams?
A: The same principle applies, though curved seams may require slightly more precision when cutting and sewing.

Q4: What about seam allowance for handles?
A: Handles typically require their own seam allowance calculation, often larger than the body of the bag for reinforcement.

Q5: Should I account for fabric thickness?
A: For thick fabrics like upholstery materials, you may need to add slightly more seam allowance to accommodate the bulk.