What You Need to Know to Fit a Sewing Pattern

In this article you will learn key tips that will make the journey to fitting your sewing patterns easier. For example, you will learn the definition of good fit; a mega cruise shipload of tips for making basic alterations; the 4 critical lengths; and several excellent fitting resources to help a sewist out!

A Truth

This fear of fit is probably why so many tutorials on YouTube and the Internet are happy to share with you how to sew a garment. BUT they gloss over or totally ignore the whole issue of fitting a sewing pattern.

And I’ve noticed that at most magazine stands, there’s an overabundance of sewing magazines dedicated to the craft of quilting.

Because after all, a quilt is easy to “fit,” right?! It is just a giant square.

BUT a woman’s body is not a square! Our bodies are more like a varied mountain range — full of hills, valleys, and curves.

And here’s a cold, hard truth…

If you buy a sewing pattern, manage to choose the “right” size, but sew it without adjusting the fit of the pattern to your body, your project is likely to be a disappointing failure!

I don’t want that for you.

So if you’re ready to overcome your fear of fitting, it’s time to get the basics of “fit…”

First, a Disclaimer

While this article is going to give you a bunch of juicy details about fit, it is still up to you do some leg work yourself.

Because, frankly, as helpful as I want to be, I am not a fit expert.

Learning how to fit yourself is an art.

And let’s be brutally honest…

Depending on your age, posture, and body shape, fit can be simple or it can be involved!

BUT here’s another comforting truth…

You only need to learn how to correct the fitting issues that apply to your figure and you can feel free to leave the rest alone! Which I think is just fabulous! Because it makes the issue of fitting a sewing pattern simpler!

What I’m going to share in this article is what I think is the best definition of a good fit and the fitting tips that I wished I had known when I first started sewing!

Then, I will share my favorite fit resources for you to explore.

Alright, be courageous and encouraged, let’s begin…

What You Need to Know About Sewing Patterns

When I started sewing, these are some of the things I wish I had known.

When I think of all the angst and grief and beautiful lengths of fabric whose “lives” could have been spared, I could just wail.

So because we are best sewing buddies, let me share these fit tips with you:

  • The Big 4 pattern companies –Butterick, McCalls, Simplicity, and Vogue– all use the same standard body measurements (BMs). Thank the lord!
  • And they draft blouse, dress, jacket, and coat patterns for a B cup bra size. So if your “girls” are smaller or larger than a B cup, a small bust adjustment (SBA) or full bust adjustment (FBA) may have to be made. Remember this!
  • However, while the Big 4 pattern companies use the same standard BMs, they can vary wildly in how much ease they include for similar styles.
  • The most difficult areas to fit are the neckline, the shoulder, the upper back, the chest, and the armholes! Remember this too!
  • If a pattern is sized small (S), medium (M), large (L), and extra-large (XL) the pattern is drafted to fit the largest size. So in the image below, a size S is drafted to fit a size 10.
Patterns - Big Four Pattern Companies

Fitted silhouettes (e.g., a sheath dress) require more adjustments than looser silhouettes (e.g., a tent dress).

In the image above, this silhouette will, generally, require fewer adjustments, because it is loose-fitting.

  • Slimmer and/or more muscular bodies require less ease than plus-size bodies!
  • The dart point’s proper distance from the bust point (BP) depends on your cup size.
  • If you have a dart, but there is still a gap, then the dart is not big enough. In other words, if you are very curvy, the dart intake will be larger than if you are less curvy.
  • If you are fitting a dress, fit the bodice and the skirt separately. Then, once all adjustments have been made join them at the waistline.
  • Fit the sleeve after you’ve fitted the bodice.
  • During the initial adjustment of a sewing pattern, you don’t have to nitpick every measurement to death. Just make sure that the proportions (length) and the width (circumference) of the sewing pattern are close to yours. Because it is at the muslin stage that you actually fine-tune fit!

Okay, I think this will get you off to a great start.

So if you’re ready, it’s time to define fit…

Good Fit Defined!

The definition of a good fit is simple.

When any garment fits you well, it means that the garment’s lengths (proportion), widths (circumferences), and depths match your body’s lengths, widths, and depths.

In other words, a sewing pattern or garment fits well when…

  • It is long or short where you are long or short (proportion or length).
  • It is wide or narrow where you are wide or narrow (width or circumference).
  • It is as deep or shallow as your curves demand (dart control).
  • The shoulder seam is at the center of your shoulder.
  • The center front (CF), center back (CB), and side seams (SS) are perpendicular to the floor.
  • The bustline, waistline, hip line, and hem are parallel to the floor all the way around.
  • The neckline and armholes lie flat against the body with no gaping or pulling.
How to Fit a Sewing Pattern

In the image above, notice how the horizontal lines at the bust, waist, and hip are parallel to the floor! And the side seams (SS), center front (CF), and center back (CB) are perpendicular to the floor!

In other words, when a sewing pattern has been adjusted to fit your body, the resulting garment will not wrinkle, pull, twist, gape, or sag! The fabric will just lay smoothly over and around the contours of your body. And you will be able to stand, sit, and move comfortably. This is fit gorgeousness!

Simple concept, right?!

I told you so!

So if you’re ready to make your sewing pattern submit to your lengths and curves, let’s talk about…

What You Need to Know About Making Basic Alterations

As I shared before, getting a good fit is all about measuring your body and then comparing it to the same area on the pattern piece!

Once you’ve chosen your starting pattern size, the next step is to make sure that the proportions (lengths) match your proportions!

This essential step is often the critical missing piece to many online garment sewing tutorials.

But if you buy a sewing pattern and choose what you think is your right size,  and sew it without making basic alterations to the proportions, it is almost certain that you will be beyond disappointed with your finished garment!

The goal is to adjust lengths (proportions) and widths of your dream garment at the pattern stage. And then, fine-tune the fit with a muslin, a test or sample garment.

Let’s begin with a few rules…

The Rules of Basic Alterations

There is no need to stress yourself out about pattern adjustments. The goal is NOT to produce a perfect fit at this stage. The goal is to help you address obvious length and width deficiencies and/or excesses.

Here are some vital tips that I’ve learned over time…

Rule #1: ONE alteration at a time, start at the top and work your way down.

Rule #2: Please limit changes to the shoulders, armholes, or neckline to those that are absolutely necessary. Always try to buy a pattern that fits you well in this area. Trust me on this!

Rule #3: Treat the front and the back of the pattern separately if you have generously blessed or have uniquely shaped body areas.

Rule #4: Before you make any alterations, extend the grainline along the entire length of the pattern piece. This will increase accuracy as you lengthen or shorten your sewing pattern.

Rule #5: If the difference is ⅛ inch or less between your body and the pattern, there is no need to adjust the pattern.

Rule #6: On multi-size patterns, do NOT blend more than two sizes.

Rule #7: Watch out for chain reactions. For example, if you lower the shoulder seam to fit a sloping shoulder, you must also lower the underarm seam by the same amount to retain the original armhole size. Or, if you adjust the neckline, then you will also have to make an adjustment to the facings if included.

Rule #8: The front and back SS must be the same length and shape.

Rule #9: Keep in mind that CB seams and SS may not straight. So use the grainline or CF as your point of reference.

Rule #10: If you’ve made the alterations correctly, the altered pattern pieces should lie flat.

Rule #11: To assess fit accurately, you need to minimize, as much as possible, any distortion of the body, such as bending, twisting, or looking down. To so, stand with your back to the full-length mirror, hold the hand-held mirror at your shoulders to check out your rearview.

Rule #12: You must fabric fit. And to do so, you need to add 3/8 inch to the 5/8 inch seam allowance at the side seams. This will increase the seam allowances at the side seams to 1 inch. You will now have a total of 2 inches at each side seam, which will allow you pin fit the garment to the contours of your body AND account for fabric ease. This is called fit insurance!

The 4 Critical Lengths

There are five critical lengths of your body that need to match the sewing pattern if you’re to have any hope of achieving a good fit…

  • Mid-shoulder to Bust Point ~ this measurement determines dart placement! (1)
  • Bust point (BP) to waist (2)
  • Waist to the fullest part of your lower body ~ this may or may not be your full hip! (3)
  • Nape to waist or back waist length (4)
How to Fit a Sewing Pattern

So one way of fitting a sewing pattern is to measure your body in certain key areas, and then comparing those measurements to the sewing pattern in those same key areas.

Order of Basic Alterations

Generally, you need to make basic adjustments in the following order:

  1. Length
  2. Dart placement
  3. Width

The reason you make length adjustments first is that it is crucial that the bustline, waistline, and hip line of the pattern is in the same place as they are on your body BEFORE you start making any width changes!

Next, make sure that any darts are pointed directly towards the curve they are shaping and at least ½ to 1 inch away from the apex, the highest point of the curve.

Once you’ve made these adjustments, you are ready to layout and pin your adjusted pattern piece, cut it out, and mark it.

You’re now ready to make a muslin, a test or sample garment.

Making a muslin will help you test the starting pattern size you selected, fine-tune the fit, and “try on” the pattern to make sure you like the style on you!

RELATED: Click HERE to learn how to take your body measurements (BMs) or width measurements accurately!

Fitting Resources for Adjusting Sewing Patterns

First, I would encourage you to approach fitting sewing patterns as a wonderful adventure, rather than with fear and apprehension. You can so do this!

I won’t lie to you…

Fitting a sewing pattern to the human body can be simple or involved, depending on the silhouette and/or your body shape.

In fact, there are books that require a crane to lift them dedicated just to the “art” of fitting a sewing pattern!

But I don’t think you need a book that heavy to fit a sewing pattern. So I want to provide you with the helpful resources that have helped me.

Here’s the thing…

There are so many ways you can approach fitting. The right way is simply the one that resonates with you and yields a beautiful fitting garment!

Personally, my understanding and approach to fitting consists of tips and tricks from many different resources and methods.

But to avoid overwhelm, you can pick one and have at it.

And the simplest way to begin is with a fitting pattern from one of the Big 4 pattern companies.

For example, Butterick 5627 and Vogue 1004 fitting patterns are stuffed full of excellent fitting information. You can’t go wrong with either!

How to Fit a Sewing Pattern

I also like McCalls 7218, a Palmer/Pletsch fitting pattern. It introduces a method called tissue fitting, where you try on the actual tissue pattern. 

With the tissue fitting method, you don’t have to make a muslin. Instead, you prepare the tissue pattern, and then try it on to correct fit issues.

I’ve not been able to locate a Simplicity fitting pattern. However, they do provide a FREE fitting guide PDF that has value.

Finally, as the ultimate fitting resource, I recommend this book…

Buy Tetsted Sewing Supplies

For me, it connected all my lost and confused dots on the matter of fit so they finally made sense! It primarily covers tissue fitting. BUT trust me, when I say this:

The juicy fitting tips you learn in it are endless, priceless, and applicable to ANY fitting method you choose!

The End

While this is not an “ultimate guide,” my hope is that this article has reduced your fear and emboldened you to conquer fit. Because yes, you can!

Finally, you have a useful definition of what constitutes a good fit.

And you now know that it all starts with proportion (lengths)!

Plus, you got some great information on how the Big Four pattern companies draft their patterns.

And that’s not all…

I gave you great resources for learning how to make personal fit alterations!

So guess what?!

If you’ve taken accurate body measurements, chosen your starting pattern size, and determined your preferred ease, you’re ready to sew a muslin.

Yes, you really should!

And remember…

Life is the ultimate red carpet event. Dress for it!

RELATED: Click HERE if you’re ready to unleash your dressmaking superpowers and learn how to sew a simple dress! Warning: This is a MEGA 5-part series!