What You Need to Know to Fit a Sewing Pattern

Hey, you!


Is the title of this article making your underarms moist?! Is your scalp suddenly itchy?! Did the flutter of a thousand butterflies in your stomach appear out of nowhere?!

Well, you’re not alone.

If there is one sewing topic that seems to elicit these symptoms and stops most of us who aspire to sew our own clothing before we even start, it is:

How the heck do you even begin to fit a sewing pattern?!

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?!

But 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 in this article, I will share…

  • what it means when a garment fits well; and
  • what you need to know to approach fitting a sewing pattern.

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

NOTE: If you’re ready to begin this journey and would like to buy my recommended tools and supplies, please click HERE!

First, a Disclaimer

This article is going to be in depth!

But honestly, as helpful as I want to be, I don’t have every fitting issue under the sun.

And most likely, neither do you!

Because let’s be brutally honest…

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

BUT the truth is this…

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.

Alright, it’s time to get fit…

What You Need to Know about Sewing Patterns

big four pattern companies: butterick, mccalls, simplicity, and vogue

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 them with you:

  • The Big 4 pattern companies –Butterick, McCalls, Simplicity, and Vogue– all use the same standard body measurements. 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, an adjustment will probably have to be made. Remember this!
  • However, while the Big 4 use the same standard body measurements, they can vary wildly in how much ease they include for similar styles.
  • If a pattern is sized small (S), medium (M), large (L), and extra large (XL) the pattern is drafted to fit the largest size.

small-medium-large sewing pattern

  • The most infuriatingly difficult areas to fit are the neckline, the shoulder, the upper back, the chest, and the armholes! Remember this too!
  • Slimmer bodies require less ease than plus size bodies!
  • 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.
  • Finally, during the initial alteration of a sewing pattern, you don’t have to nitpick every measurement to death. Just make sure that the proportions and width 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, Finally!

The definition of 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;
  • it is wide or narrow where you are wide or narrow; and
  • it is as deep or shallow as your curves demand.

illustration of good fit

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! This is fit gorgeousness!

Easy, right?!

I told you so!

So fitting a sewing pattern begins with measuring your body in certain key areas, and then comparing those measurements to the pattern in those same key areas.

Proportion is not about height. For example, a short person can have long legs and a tall person can have a short torso relative to their height.

And when a sewing pattern has been adjusted to fit your body, the resulting garment will not wrinkle, pull, or sag!

And you will be able to stand, sit, and move comfortably.

This is the definition of a good fit! However, this definition may seem a bit old school. Because today, many women’s preferred fit is very, very snug with obvious wrinkling and pulling.

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

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 the result!

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…

  • Treat the front and the back of the pattern separately, especially if you have generously blessed or have uniquely shaped body areas.
  • If the difference is 1/8 inch or less between your body and the pattern, there is no need to adjust the pattern.
  • Before you make any alterations, extend the grain line along the entire length of the pattern piece. This will increase accuracy as you lengthen or shorten your sewing pattern.
  • On multi-size patterns, do NOT blend more than two sizes. If you need to blend more than two sizes, you probably need to go up a pattern size.
  • 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.
  • Center back seams and side seams are often not straight. So use the grain line or center front (CF) as your point of reference.
  • All tissue pattern pieces must be flat after any alteration.
  • Check that the front and back pattern pieces are the same lengths at the shoulder and side seams.

The 4 Critical Lengths

There are four 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!)
  • Bust point (BP) to waist
  • Nape to waist (back waist length)
  • Waist to the fullest part of your lower body (this may or may not be your full hip!)

In the image below, I’ve given you an example of the mid-shoulder to bust point (1) and bust point to waist (2) lengths as it compares between the female form and a sewing pattern:

comparing two critical body lengths on the female body and on the sewing pattern


Other important lengths include:

  • Shoulder slope
  • Shoulder length

I’ve seen many creative and some complicated ways of determining your shoulder slope. But if you have a ready-to-wear (RTW) garment in your closet that fits you well in the upper body, you in luck! This is how you can use that garment to determine your shoulder slope:

shoulder slope example on a ready-to-wear dress

And three other important widths are:

  • Sleeve width (the circumference of biceps)
  • Shoulder Point (SP) to the elbow
  • Elbow to the wrist bone

Okay. Now that you understand proportion, let’s discuss the order in which pattern alterations MUST take place…

Order of Basic Alterations

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 hipline 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, which is 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!

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!

First, the simplest resource is a fitting pattern from one of the Big 4 pattern companies. Butterick 5627 and Vogue 1004 guide sheets are both stuffed full of excellent fitting information.

two fitting patterns and guide sheet

I also like McCalls 6355. It goes into a technique called tissue fitting, where you try on the actual tissue pattern. While I’m not fond of tissue fitting,  the guide sheet information is priceless!

I hope you live near a Joann. Because I don’t recommend you ever buy sewing patterns at regular price or even 40% off. Because if you wait for a sale (which happens quite frequently), you can get Simplicity, Butterick and McCalls’ patterns for a steal at $1.99 and Vogue for $4.99!

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

Finally, I would recommend any of my favorite sewing reference books. They are also rich not only in all things sewing-related but also include excellent sections on how to fit sewing patterns…

sewing books with excellent fitting sections

Well, I think I’ve done well by you!

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!

In the next article, I will take you step-by-step through how I sew a muslin.

And remember…

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

RELATED: Click HERE to learn everything you need to know about sewing patterns so that you can flaunt the perfect fit!

RELATED: Click HERE to learn everything you need to know about fabric to sew insanely gorgeous dresses!

RELATED: Click HERE if you’re ready to begin this journey and would like to buy my recommended tools and supplies!

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