Sewing Pattern Scale Converter

Convert sewing pattern scales. Calculate correct percentage to print or adjust patterns based on original scale vs desired print size.

Note: This calculator helps convert between pattern scales. Common scales are 1:1 (full size), 1:2 (half size), 1:4 (quarter size), etc. Enter the scale ratio (the number after the colon).
Enter the number after the colon (e.g., 4 for 1:4 scale)
Enter the number after the colon (e.g., 2 for 1:2 scale)
Enter a measurement from the original pattern to see the adjusted measurement

How This Tool Works

This sewing pattern scale converter calculates the correct print percentage to convert between different pattern scales. It determines how much to scale up or down when printing patterns.

The calculator uses the ratio between the original scale and desired scale to determine the print percentage. For example, converting from 1:4 scale to 1:2 scale requires printing at 200% (doubling the size).

Common Pattern Scales

  • 1:1 (Full Scale): Pattern is actual size - no scaling needed
  • 1:2 (Half Scale): Pattern is half the actual size - print at 200% for full size
  • 1:4 (Quarter Scale): Pattern is quarter size - print at 400% for full size
  • 1:5 (Fifth Scale): Pattern is one-fifth size - print at 500% for full size
  • 1:10 (Tenth Scale): Pattern is one-tenth size - print at 1000% for full size

Formula

The calculation is based on:

Scale Percentage = (Desired Scale / Original Scale) × 100
Print Percentage = Scale Percentage
Adjusted Measurement = Original Measurement × (Desired Scale / Original Scale)

Example: Converting from 1:4 to 1:2 scale:

Scale Percentage = (2 / 4) × 100 = 200%
Print at 200% to get 1:2 scale from 1:4 pattern

Printing Tips

  • Check Printer Settings: Ensure your printer can handle the required scale percentage.
  • Verify Measurements: Always measure a known dimension after printing to confirm accuracy.
  • Print in Sections: For very large scales, you may need to print in sections and tape together.
  • Use Quality Paper: Use appropriate paper weight for pattern tracing and cutting.
  • Test Print: Do a test print of a small section first to verify the scale is correct.

FAQ

  • What is a pattern scale?
    Pattern scales are ratios that indicate the size of a pattern relative to the finished garment. Common scales include 1:1 (full size), 1:2 (half size), 1:4 (quarter size), and 1:5 (fifth size). The number after the colon shows how many times smaller the pattern is than the actual size.
  • How do I use the print percentage?
    When printing your pattern, set your printer's scale/zoom setting to the calculated print percentage. For example, if the result is 200%, set your printer to print at 200% scale. This will enlarge the pattern to your desired scale.
  • What if my pattern doesn't have a scale listed?
    If no scale is listed, the pattern is likely 1:1 (full size). Measure a known dimension (like a seam allowance or marked measurement) and compare it to the actual size to determine the scale.
  • Do I need to adjust seam allowances?
    Seam allowances are usually included in patterns and scale proportionally. However, some patterns may need manual adjustment. Always check critical measurements like seam allowances, darts, and key dimensions after printing.
  • Can I convert between any scales?
    Yes, you can convert between any scales. However, very large scale changes (e.g., 1:10 to 1:1) may result in very large print percentages. Make sure your printer can handle the required scale, or consider printing in sections and taping together.

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