Sewing Pattern Sizes Explained: How to Choose the Right Size

The short answer: choose your sewing pattern size by body measurements, not the size you buy in shops. Measure chest (bust), waist and hip, and for children also height, then compare the numbers with the pattern's size chart. Pattern sizes often don't match ready-to-wear sizes. Many traditional envelope patterns run about two sizes smaller than department store clothing, so picking your usual shop size is the most common reason homemade clothes turn out too tight.

Marina, the designer behind Frocks & Frolics, taught textiles for many years. She has watched plenty of students cut out "their size" and refuse to cut the bigger size the measurements called for. This guide explains why pattern sizes work differently, how to measure properly, and what to do when your measurements fall between sizes.

Why pattern sizes don't match shop sizes

Marina has used all the big paper-envelope pattern companies: Burda, McCall's, Simplicity, New Look and Vogue. Their measurement charts trace back to much older sizing standards. Over the decades, shop sizes have drifted, partly because we all like to feel smaller than we are. Sewing pattern charts didn't follow them, so the gap between the two has grown. In Marina's experience, envelope pattern sizes are now about two sizes smaller than average department store sizes.

The fix is simple: ignore the size label and use a tape measure.

How to measure correctly

For adults and teens

• Bust: around the fullest part, keeping the tape level across the back
• Waist: around the natural waist, the narrowest point
• Hip: around the fullest part of the hips and seat

For children

• Height: standing straight against a wall, without shoes
• Chest: around the fullest part, under the arms
• Waist: around the natural waist, which on small children is often hard to spot, so measure where trousers sit comfortably
• Hip: around the fullest part of the bottom

Measure over underwear or a thin layer, keep the tape snug but not tight, and write the numbers down with the date. Children change fast.

Understanding ease

A pattern's finished garment is always bigger than the body measurements. That extra room is called ease:

• Wearing ease lets you move, breathe and sit.
• Design ease creates the style, such as the fullness of a tunic or the swing of an A-line dress.

This is why you choose by body measurements. The pattern already adds the right amount of ease for its style. Knit patterns may have little or even negative ease, because the fabric stretches.

What if you're between sizes?

Most people are, and it's normal:

• Choose by the measurement that matters most for the garment: chest or bust for tops and dresses, hip for skirts and trousers.
• Blend between sizes where your measurements cross from one size to another. For example, you might use one size at the bust and the next at the waist, drawing a smooth line between them.
• Check the finished garment measurements if the pattern gives them, and compare them with a garment that fits well.

Most Frocks & Frolics patterns include a separate PDF file for every size, so you only print what you need. To blend two sizes, print both and trace a smooth line between them. The Sophia Faux Wrap Dress is multi-size and designed for merging sizes. Its bust is always drafted one size up from the waist, which makes it especially friendly for curvier figures.

Turn-up sleeves on the Dakota Pea Coat give children room to grow.

Sizing tips for children's clothes

• Height and chest matter more than age. Age labels are a guide only. Two six-year-olds can be several sizes apart.
• Room to grow: going up one size usually works for coats, dungarees and skirts with elastic waists. Designs with features that grow with the child help too, like the turn-up sleeves on the Dakota Pea Coat, which let a coat keep fitting for longer.
• Don't size up for fitted pieces. Garments like a lined bodice or a shirt with a collar look best in the correct size.

Before you cut: check your printout

A perfect size choice won't help if the pattern prints at the wrong scale. Print PDF patterns at 100% or "actual size", never tick "fit to page", and use Adobe Acrobat Reader. Built-in PDF viewers can shrink the pattern. Our PDF printing help page has the exact settings.

Frequently asked questions

Why is my sewing pattern size bigger than my clothing size?

Many pattern companies still use older measurement charts, while ready-to-wear sizes have grown more generous over time. Marina's rule of thumb is that envelope pattern sizes run about two sizes smaller than shop sizes, so choose by measurements.

Should I choose a pattern size by bust or waist?

For tops and dresses, start with the bust or chest measurement, because it's the hardest area to adjust, and alter the waist if needed. For skirts and trousers, start with the hip.

How do I choose a size for a children's sewing pattern?

Measure height, chest, waist and hip, and compare them with the pattern's chart rather than going by age. If the child is between sizes and the garment is loose-fitting, the larger size gives room to grow.

Do Frocks & Frolics patterns include all sizes?

Yes. The size range is listed on each pattern page, and most patterns include every size as its own PDF file in both A4 and US Letter format, so you can print only the size you need. For more about how the patterns work, see our FAQ.

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