Adjusting the size of a sewing pattern is a common and essential skill for any home sewer. You can alter a pattern by adding or subtracting width and length, often using specific measurement points and techniques to ensure an accurate fit. This guide will walk you through the process.

Mastering Sewing Pattern Adjustments: A Step-by-Step Guide

Sewing your own clothes offers incredible personalization, but often, commercial patterns don’t fit perfectly right out of the envelope. Learning how to adjust sewing pattern sizes is key to achieving a professional and comfortable finished garment. Whether you need to make a pattern larger or smaller, or simply tweak it for your unique body shape, these techniques will empower you.

Why Adjust Your Sewing Patterns?

Commercial patterns are drafted for standard body measurements. However, very few people fit these standards exactly. You might be taller or shorter than the pattern’s intended height, have a fuller bust, a wider waist, or broader shoulders. Pattern alteration ensures your handmade garments look and feel as good as they would from a high-end boutique.

Common Fit Issues and Solutions

• Too short or too long: This is a frequent problem, especially for those outside the average height range.
• Too tight or too loose: Adjusting the overall circumference of the garment is crucial for comfort.
• Proportion issues: Sometimes, a pattern might fit in one area but be off in another (e.g., a long torso with short legs).

Understanding Your Measurements

Before you can adjust a pattern, you need accurate body measurements. Use a flexible measuring tape and wear minimal clothing. Key measurements include:

• Bust: Measure around the fullest part of your bust.
• Waist: Measure around your natural waistline.
• Hips: Measure around the fullest part of your hips.
• Height: Stand straight and measure from the top of your head to your feet.
• Inseam: Measure from your crotch down to your desired hem length.

Compare these to the measurements listed on the pattern envelope. The pattern’s measurements will indicate which size to start with.

How to Make a Pattern Larger (Adding Fullness)

When a pattern is too small, you need to add ease and width. The most common place to do this is along the side seams.

Adding Width to Bodice and Skirt Pieces

1. Identify Seam Lines: Locate the side seams of your pattern pieces (front and back bodice, skirt, etc.).
2. Draw Alteration Lines: Draw a horizontal line across the pattern piece, roughly halfway between the bust/waist and the armhole/hem. Draw another horizontal line at the hip level if needed.
3. Slash and Spread: Carefully cut along these horizontal lines, stopping just short of the side seams.
4. Spread the Pieces: Gently spread the cut sections apart. The amount you spread determines how much width you add. For example, to add 2 inches to the total circumference of a bodice, you would spread each side seam by 1 inch (½ inch on each side of the slash).
5. True the Side Seams: Use a ruler to draw a new, straight side seam line connecting the original seam lines at the top and bottom.
6. Add Paper: Tape pattern paper or plain paper to the opened gaps to fill them in. Redraw any affected grainlines.

Adding Length to Bodice and Skirt Pieces

1. Draw Alteration Lines: Draw a horizontal line across the pattern piece, typically at the lengthen/shorten line indicated on the pattern. If none is present, draw one about midway between the bust and the waist for bodices, or midway between the waist and the hip for skirts.
2. Slash and Spread: Cut along this horizontal line, stopping just short of the side seams.
3. Spread the Pieces: Spread the cut sections apart by the desired amount of length you need to add.
4. Add Paper: Tape pattern paper into the opened gap and redraw the side seam if necessary.

How to Make a Pattern Smaller (Subtracting Fullness)

To make a pattern smaller, you will reduce ease and width by folding out excess fabric.

Subtracting Width from Bodice and Skirt Pieces

1. Draw Alteration Lines: Draw horizontal lines across the pattern piece as described for adding width.
2. Fold Out Excess: Instead of spreading, fold the pattern piece along these lines. Overlap the edges by the amount you need to remove. For example, to remove 2 inches from the total circumference, overlap each side seam slash by 1 inch (½ inch on each side of the fold).
3. True the Side Seams: Use a ruler to draw a new, straight side seam line over the folded section.
4. Secure the Folds: Tape the folds securely in place.

Subtracting Length from Bodice and Skirt Pieces

1. Draw Alteration Lines: Draw a horizontal line across the pattern piece at the lengthen/shorten line.
2. Fold Out Excess: Fold the pattern piece along this line, overlapping the edges by the amount of length you need to remove.
3. Secure the Folds: Tape the fold securely.

Adjusting Sleeves

Sleeves can also be too long, short, or wide.

• Adding/Subtracting Length: Use the lengthen/shorten line on the sleeve pattern piece, similar to bodices and skirts.
• Adding/Subtracting Width: Slash vertically down the center of the sleeve pattern piece from the hem to the underarm. Spread or overlap to adjust the width, then true the side seams.

Specific Pattern Adjustments

Different pattern pieces require slightly different approaches.

Adjusting for a Full Bust

If your bust measurement is significantly larger than your high bust measurement, you may need to perform a full bust adjustment (FBA). This involves adding dart equivalents to the front bodice piece to accommodate the extra fabric. This is a more advanced technique, often involving adding a new dart or extending an existing one.

Adjusting for a Full Seat

For skirts and trousers, a larger hip and seat measurement might require a full seat adjustment. This typically involves adding width to the center back seam of the pattern pieces.

Adjusting for a Long Torso

If you need to add length to the torso, consider adding it at the waistline of both the bodice and the skirt/trouser pattern pieces. You can also add length above the bust or below the waist.

Tips for Successful Pattern Adjustments

• Always work on a copy: Never alter your original pattern tissue. Trace the pattern pieces onto new paper or use a second copy.
• Measure twice, cut once: Accuracy is paramount. Double-check your measurements and your alterations.
• Consider grainlines: Ensure your grainlines remain parallel to the fabric’