How to Grade a Sewing Pattern into Multiple Sizes

Grading is how one pattern becomes a full size range. If you design garments for a small brand or sell patterns, you will need to grade a sewing pattern into sizes sooner or later. This guide explains how grading works, the two main methods, and how to check a size run before production.

What pattern grading is (and is not)

Grading takes a base pattern, usually a medium, and makes it larger and smaller in planned steps. The aim is to keep the same style, proportions and balance across every size.

Grading is not the same as fitting. Fitting changes a pattern for one particular body. Grading changes it for a range of bodies according to a size chart. A well-graded set still needs a good base pattern; grading will not fix a poor fit, it will copy it into every size.

Start with a size chart and grade rules

Before you touch the pattern, decide the measurements for each size. Your size chart is the foundation.

• List every size in your range, for example XS to XXXL.
• For each size, record bust, waist, hip, shoulder, lengths and sleeve.
• Work out the difference between neighbouring sizes. This difference is the grade.

Grades often grow larger at the top of a range. The jump from XL to XXL may be bigger than from S to M, because bodies change differently as sizes increase. Write these increments down as your grade rules, and divide each one across the pattern pieces. For example, a bust increase is shared between the front and back, and between the left and right halves if pieces are cut on the fold.

If you need help reading or building the chart itself, see our guide on how to measure a body accurately.

Method 1: Cut and spread

This is the most intuitive manual method and is good for learning.

1. Trace the base pattern.
2. Draw slash lines through the piece, vertically for width and horizontally for length.
3. Cut along the lines and spread each section by the grade amount for the next size up, or overlap it for the next size down.
4. Tape the pieces to new paper and redraw smooth outlines.

It is clear to see what is happening, but it is slow and curves need careful truing afterwards.

Method 2: Point shifting (nesting)

Professional graders usually move key points instead of cutting.

1. Mark the important points: shoulder neck point, shoulder point, underarm, waist, hip, hem corners.
2. For each point, move it horizontally and vertically by the amount set in your grade rules.
3. Connect the moved points, copying the shape of the original curves.
4. Repeat for every size, so the outlines sit inside each other like nested rings.

A nested set makes errors easy to spot. If one size line crosses another or the spacing jumps unevenly, something is wrong.

Check every graded size

Grading mistakes tend to hide in seams that join two pieces. Before releasing a size run, check:

• Seam lengths match. Front and back side seams, and sleeve cap to armhole, should still fit together in every size.
• Notches move with the seams. Re-mark notches after grading.
• Grainlines stay parallel to centre front and centre back.
• Necklines still fit the head in the smallest size and do not gape in the largest.
• Fabric use. Larger sizes may no longer fit across a narrow fabric width. Re-check the layout.

Then sew samples. At minimum, make the smallest, the base and the largest size. If those three work, the sizes between them usually will.

Using software to produce a graded set

Manual grading is a valuable skill, but it is time-consuming across seven sizes and several styles. Pattern software can produce each size directly from its measurements instead of moving points by hand.

On Digital Creation, every design can be generated in XS, S, M, L, XL, XXL and XXXL, and an "All sizes" ZIP is available for graded sets. If you are working from a garment you have seen online, the photo to pattern tool reads the product photo and its size chart, lets you check and edit every number, and then produces patterns for every size on the chart. Downloads include a DXF file in millimetres with separate layers for cut, seam, fold, grain, notches and text, which is helpful if you or your cutter work in CAD.

Frequently asked questions

Which size should be the base size?

Most graders use the middle of the range, often M, because grading errors grow with distance from the base. Starting in the middle keeps them small at both ends.

How many sizes can I grade from one base?

There is no fixed limit, but very wide ranges often benefit from two base patterns, one for smaller sizes and one for larger sizes, because body proportions change.

If you need a size run quickly, explore the designs in the pattern builder and see the Pricing page for plans that include downloads.