Pattern grading – all you need to know 6

If you ever wondered how to make a sewing pattern bigger or smaller, which is also known as pattern grading, you are at the right place.

In this article, we are going to go through different methods of pattern grading, how to do it and which one to chose. We are also going to touch on how to grade more complex multi-size patterns and review some further resources on pattern grading. 

How to make a sewing pattern bigger or smaller

Grading sewing patterns is the act of making a pattern bigger or smaller so that it fits your body measurements.

Pattern grading is a very interesting process because it’s not just a matter of gradually increasing or decreasing between sizes. It takes into consideration the nature of human body proportions and how they grow in different sizes.

How much you are supposed to grade a pattern depends on your body measurements, but also on the human growth proportions. This means that your body grows differently in different areas and in a different age.

For example, a child’s body grows mainly in height and less in width. While a woman’s body grows in width much more than in height. Also, the bust and waist grow more significantly than the neck and the shoulder.

That’s why patterns are usually graded in groups like baby, children, misses, women and also regular, petite and tall.

If we want to grade our pattern to fit, we don’t just need to scale it, we need to take into consideration how and where the body grows.  If you just scale let’s say a bodice to fit the horizontal measurements like bust, waist, and hips, you would probably end up with a shoulder that is too long and an oddly shaped armhole.

Do you need to grade a sewing pattern to fit?

Sometimes, if the pattern doesn’t fit your measurements, you might need to make adjustments to the pattern that are different from grading.

For example, if the pattern would fit everywhere except the bust, you most probably would need to make a full bust adjustment (FBA) and not to grade the whole pattern. 

Or, if you are taller or shorter, you might need to lengthen/shorten at the torso or crotch area, whatever you might be working on.

If you are using a nested pattern (a pattern which has the smaller sizes nested into the bigger ones) and your measurements spread between different sizes already included in the pattern, you need to blend between sizes.

Blending is when you join the pattern lines for different sizes to respond to your body measurements. Here is an example.

If none of the above is your case, then you most probably need to grade the whole pattern.

How to measure for pattern grading?

To grade an existing pattern accurately, you need to have in mind all the design elements (like gathering and pleats) that add volume to the pattern as well as the wearing ease included. Then, you need to consider how they relate to the body measurements for that size.

For example, if you are about to grade size 10 up to size 14, measure the paper pattern in size 10 and compare to the body measurements for that size in the pattern description.

You are going to find out that there is a difference.

Many patterns come with body measurements charts and finished garment measurement charts.  Consider the amount for ease and design to your measurements in order to get the right pattern dimensions.

Calculate the difference between the pattern you have and the one you need. This difference is how much you need to grade the pattern up (or down).

No matter which of the methods below you prefer, make sure to true the graded pattern and make a muslin before cutting your good fabric. For best results, try not to go for more than two sizes, because the pattern can get distorted. If you need more than two sizes, grade the pattern once. Then, grade the new size once again until you reach the size you want. 

Also, if you need to grade a girls pattern into a woman size, it might be better to redraft the pattern instead of just grading it up, because the pattern was designed with different body proportions in mind.

Methods of pattern grading

There are four basic methods to grade a sewing pattern up or down: the slash and spread method, the shift method, grading nested (evenly graded) patterns and computer grading. You can use each one to get an accurately graded pattern, no matter if you are a home sewist or an independent designer.

The slash and spread method

This is one of the most popular way to resize a pattern. Its name suggests what you have to do. First, you need to draw lines through the pattern in locations where the body usually grows or shrinks. Then, you need to cut through those lines and spread or overlap the pattern pieces.

What you are going to need is just a clear grid ruler, some tape, paper scissors, and a pen.

You can see different variations of the position and number of the lines through which you are supposed to cut and spread. There also are different grading rules thought in different books and schools.

In general, the slash lines are drawn at approximate positions where the body tends to grow or shrink.

Here is how I like to do it.

Increasing or decreasing the size of a bodice

To change the size of a bodice pattern (which is usually for ¼ of the body), you need to divide the difference by four. For example, if you measured your bust to be 48 inches and the pattern goes up to a bust of 44 inches, you need to increase with 4 inches all around the body.

And since you are working with the pattern for ¼ of the body, you need to divide those 4 inches by 4. That makes an overall increase of 1 inch. Then, you need to spread that one inch across the bodice at the slash and spread lines.

Draw three vertical lines through the bodice: one from the neckline down (1) to the waistline, one from the shoulder down to the waist (2), and one from the lower part of the armhole curve down (3). Those lines have approximate positions, so don’t worry too much where to place them. Just be careful not to go through the waist dart if there is one because this can distort the pattern.

Then, draw two horizontal lines – one from center front to the armhole (4) and one from center front to the side seam (5).

Cut through the lines and divide that one inch across the lines as shown on the image above. Add ¼ inch at lines 1 and 2. Add ½ inch at line 3. Add ¼ inch at each horizontal line (lines 4 and 5).

Redraw the pattern following the new outlines. Smooth at the curves and refine the edges. 

Here is an example in centimeters.

Let’s say we need to upgrade the pattern with 4 cms. For a ¼ bodice that would be 1 cm. We spread at lines 1,2, 4 and 5 with ¼ or 0.25 cms and with ½ or 0.5 cms at line 3.

If you need to make the pattern smaller, instead of spreading the pattern pieces, overlap them following the same instructions.

Make the same adjustment to the back bodice pattern piece as well.

Increasing or decreasing the size of the sleeve

To adjust the sleeve so that it fits into the graded bodice pattern, you need to make similar changes at the same places.

Draw three horizontal lines midway between bicep and the cap (line 1), between the bicep and the elbow (line 2), and between the elbow and the hem (line 3). Draw vertical lines that are perpendicular to the grainline at these approximate positions: between the seam and front notch down to the hem (line 4), seam and back notch down to hem (line 5), and the cap sleeve to hem at the center (line 6). If the pattern comes without notches, draw the lines at approximate positions.

Let’s say we are grading this sleeve to match the bodice above. We have the same inch to spread overall the sleeve. Cut through the lines and divide that one inch across the lines as shown on the image below. Add ¼ inch at each horizontal line (lines 1, 2 and 3). Add ¼ inch at line 4 and 5. Add ½ inch at line 6.

This way the sleeve curve will increase with two inches. We’ve increased the armhole length with 3/4 inch at the front and the same at the back. That makes an overall extension of 1 ½ inch. The overall extension of the sleeve curve is 4 x ¼ +½ = 1 ½ inch. It’s the same as the armhole, so it should match nicely.

Redraw the sleeve following the new outlines. Smooth at the curves and refine the edges.  Always walk and true the sleeve with the armhole curve to see if they match.

Here is the example in centimeters.

We’ve added 0.75 cm to the armhole curve at both front and back bodice. It amounts to 1.5 cm along the armhole. The overall extension of the sleeve curve is 4 times ¼ +½ = (4×0.25) + 0.5 = 1.5 cm. It matches the armhole, but make sure by walking and truing your pattern.

How to make a skirt pattern bigger or smaller

To change the size of a skirt pattern (which is usually for ¼ of the body), you need to divide the difference by four. Let’s use the same example and increase with 4 inches all around the body.

The front skirt piece is for ¼ of the body, so you need to divide those 4 inches by 4. That makes 1-inch overall increase. Then, you need to spread that one inch across the skirt front at the slash and spread lines.

Draw three vertical lines through the skirt from waistline to hem: two between the center front and the dart (lines 1 and 2), and one between the dart and the side seam (3).

Then, draw two horizontal lines – one at the hipline (4) and one at mid-thigh (5).

Cut through the lines and divide that one inch across the lines as shown on the image above. Add ¼ inch at line 1 and 2. Add ½ inch at line 3. Add ½ inch at each horizontal line (lines 4 and 5).

Here is an example in centimeters.

Let’s say we need to upgrade the pattern with 4 cms. For a ¼ skirt that would be 1 cm. We spread at the lines and leave 0.25 cm at lines 1 and 2. Then, leave half a centimeter at lines 3, 4 and 5.

Redraw the pattern, following the new outlines.

If you need to make the pattern smaller, instead of spreading the pattern pieces, overlap them following the same instructions.

Make the same adjustment to the back skirt pattern piece as well.

How to make a pants pattern bigger or smaller

To change the size of a pants pattern (which also is usually for ¼ of the body), you need to divide the difference by four. Using the same example, we need to increase with 4 inches. Divide those 4 inches by 4. That makes 1-inch overall increase. Then, spread that one inch across the pants front/back at the slash and spread lines.

Draw three vertical lines through the front from waistline to hem: two between the center front and the dart if there is one (lines 1 and 2), and one between the dart and the side seam (3).

Then, draw two horizontal lines – one at the hipline (4) and one at mid-thigh (5). Add one more vertical line at the midpoint of the front/back crotch extension (line 6).

To grade the back pattern piece, follow the same steps.

Cut through the lines and divide that one inch across the lines as shown on the image above. Add ¼ inch at lines 1 and 2. Add ½ inch at line 3. Add ½ inch at each horizontal line (lines 4 and 5). At the mid crotch line, add ⅓ inch for the front and the ½ for the back pattern.

Here is an example in centimeters.

Let’s say we need to upgrade the pattern with 4 cms. For a ¼ pants that would be 1 cm. We spread at the lines and leave 0.25 cm at lines 1 and 2. Then, leave half a cm at lines 3, 4 and 5. At line 6, leave ⅓ for the front crotch (0.3 cm) and ½ for the back crotch (0.5 cms).

Redraw the pattern following the new outlines.

If you need to make the pattern smaller, instead of spreading the pattern pieces, overlap them following the same instructions.

Grading nested (evenly graded) patterns

Evenly graded are those patterns that have the same distance between sizes in any point (for example the bust) and you can draw a straight line through the sizes at that point (see the image below). They are also called nested because smaller sizes are arranged into the bigger sizes. Most commercial patterns are evenly graded.

It’s fairly easy to find out if the pattern you are dealing with is evenly graded. Looking at the example below, I can tell that the pattern increases with the same distance in every size. The neckline rises with 1/16 inch in every size, the hemline drops with 1/4 and the side grows with 1/4 as well and so on. 

Let’s say you’ve measured and found out that you need to go one size up.

Draw straight lines at all angles through all sizes. Then, draw a couple of lines through the curves as well. Mark at any point where the pattern changes.

Measure how much the patterns changes with between sizes at that line. Following the line, mark with a dot at the same distance you’ve measured.

Connect the dots with a smooth curve at the neckline and armhole. Connect all other dots with a straight line and make sure the angles are right.

If you need to grade with 2 or 3 sizes for example, double or triple the distance between patterns at every point.

The shifting method for pattern grading

Pattern shifting is the act of increasing or decreasing the size of a pattern by tracing and moving it up, down, left or right by a measured distance and then retracing the pattern in a new size.

To make a smaller size, you first trace the original pattern. Then, move it in and up from a fixed point which is usually the center front or back (for a bodice).

To make the size bigger, trace the pattern and then move it out and down. The distance you are supposed to move it is a fraction of the overall difference.

This method gives as accurate results as the slash and spread method, but IMO requires more calculations. There are special grading rulers to simplify the process.

I know designers that prefer this method to grade. It might be the best match for you, too.

If you want to learn more about this method of grading, check the resources I list below.

Simplified grading of a bodice

This method is an easy way to grade manually, especially when you are in a hurry. It’s not one that I’ve seen in many books for grading, but I like it because it is fast and produces accurate results, especially for simple patterns.

If you are willing to stick to more popular solutions, please use one of the methods above.

But if you to give this one a try, here is how to do it.

Let’s say you have a size 8 and you want to grade up to a 10. Shift ⅛ of an inch up at the neckline, then ⅛ of an inch out for the shoulder (see the image). Then ⅛ of an inch down the armhole and ¼ out at the side. Go down with ¼ for the hem. Drop the waist down with ⅛ of an inch per size and move the dart (if there is any) ¼ out and ⅛ down.

Keep the center front/center back on point. Retrace the new pattern size following the new points. These measurements are for a ¼ bodice. Add them to both sides of the body (front and back).

In cms, that would be 0.3 cms for ⅛ of an inch and 0.6 cms for ½.

For larger sizes (size 16 and up), replace ⅛ with ¼ and ¼ with ½.

Computer grading

Computer grading is, in my opinion, the fastest and easiest way to grade patterns. But, it requires some specialized knowledge about the specific software you are going to use. Unfortunately, the specialized software for grading sewing patterns is very expensive.

But you can quite well replace it with a much cheaper software for digital design. To digitalize and grade my patterns, I use Adobe Illustrator CC and I really like it. Although it is not created with pattern design and grading in mind, there is a set of tools that you can use to get great, accurate results with sewing patterns.

As with any other software,  there is a learning curve to grasp it. But once you get to know the right tools and how to use them, you can spend considerably less time than if you were doing it manually.

I happen to know that there are other types of software that are completely free (open source) and can replace Adobe Illustrator, but I haven’t used any of those and can’t give an opinion. If you can, please share what you think in the comments below.

Level up your pattern grading skills

No matter how many pieces are there in a pattern or how complicated the design is, all patterns are based on onе of the main slopers. That’s why you can grade it up or down just as a basic pattern.

Grading a multi piece pattern

I made a pattern recently that I had to grade in girls and women sizes. It is a multi piece pattern and I graded from toddlers’ to girls’ sizes 14 and women sizes 0 to 3X plus. In fact, the pattern grading process inspired this post.

It sure was a challenge to my grading skills. I had to grade in toddlers sizes first, then in girls’ up to size 14. I also had to grade in regular women sizes and then in plus sizes as well. On top of that, it was a multi piece pattern.  

So how do you grade a multi piece pattern? The same way you grade a one piece bodice, pants or skirt pattern.

Here is the dress I was working on. I used the slash and spread method to grade it. 

First, I stacked the details on top of each other to create the shape they are going to take when sewn. Then, I draw the slash and spread lines at the positions. I draw 6 lines instead of three because this pattern has a whole front. I also draw three horizontal lines because the pattern is for a dress (which combines the bodice and the skirt).

Then, I slash, spread, and redraw the pattern in the new size.

Resources on pattern grading

I’m a self-thought pattern maker and designer. To make my first patterns, I would copy the garments I like. Eventually, I found great resources on pattern making, but I had a hard time finding good resources on pattern grading.

That’s why I’m sharing some of them. Here they are.

Some pattern grading books

Concepts of pattern grading is one of my favorite books on the matter. It goes over the grading rules in detail. It is well illustrated with charts and diagrams. There are exercises to help you better understand the grading rules.

Manual grading techniques and computer grading are both equally included in the book. 

It is professionally written and can help you step up your pattern making game. For that reason, it may not be the best match for you if you are looking to learn to grade commercial patterns or if you are an absolute beginner.

In that case, some of the courses above may be a better source of knowledge.

Grading techniques for fashion design is another one I like. The content is well explained and easy to read. There are step by step instructions which are clearly illustrated. 

It goes over the grading rules for many different designs as reglans, kimono and different styles of skirts and pants.

I find that one to be appropriate for beginners as well as a reference for more experienced pattern makers.

Make Your Own Dress Patterns

Although this book is not particularly on pattern grading, there are some grading rules included in the final chapters that I find easy to follow and use. It includes a lot of information on how to alter and style your basic slopers, but does not teach you how to draft them from scratch.

Pattern grading for fashion design

Pattern grading for fashion design is the act of changing a pattern that has been tested and approved into different sizes for mass production.

We start developing the pattern in one basic size, usually between small and large. Once we make sure the pattern fit is perfect into that size, we start grading the pattern. This is the process of turning this basic pattern into all the different sizes that you are going to offer.

When I used to work into the designing department of a big apparel factory, there were 5 different teams to carry out this process.

First, there is the design department where the designers would create the sketch. Then, there is the pattern making team where the designer and the patternmaker would collaborate on the final version of the pattern into a certain size.

Next, the pattern heads for fitting, where the dressmaking department produces the fitting sample by following the pattern and the sewing instructions. Then, we would try the fitting sample on a dress form or a model and make some adjustments until the fitting sample is perfected. The changes are applied to the basic pattern as well.

Then, there is the graphic design department, where they would digitalize the design and the pattern.

Next, the basic pattern goes into the computerized pattern grading department, where a CAD/CAM computer system is used to grade the pattern in all the sizes we are going to offer in our clothing line.

The pattern gets printed and then tested again with fitting samples in all sizes. Then, the technologist would write all the specifications, cutting and sewing instructions. And then, phew! it heads to mass production.  

So, if you want to work in the fashion industry, chances are that either someone else is going to grade the patterns or if that one is you, you will have to learn how to use some specialized software like Gerber to do it.

If you happen to sew for yourself and family and want to make a pattern smaller or bigger, some of the methods described above will do the job just fine.

If you are an independent designer and want to grade your patterns in sizes, you know that the amount of manual work involved is enormous. That’s why you might want to consider computer grading.

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Hi sewing friends, Daniela here! As a passionate sewist and pattern maker, I love to empower fellow creators to sew their dream wardrobes. Join me on a fun journey where we unlock our creativity, stitch by stitch.

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I hope you enjoyed this pattern-making lesson. Happy sewing!

Related posts:

1. How to make a skirt pattern like an expert
2. 3 Easy Ways To Draft a Harem Pants Pattern
3. How to draft a circle skirt pattern
4. Draft and sew a collar and a collar stand

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