What Is Garment Grading?
Grading is the process of scaling a pattern from its base size up and down to create the other sizes in a range. Rather than drawing a new pattern for every size, a pattern maker develops and perfects one size, then applies a set of grade rules: planned increments by which each measurement grows or shrinks between sizes. The result is a consistent size set in which every size relates logically to the next.
Good grading keeps the design’s proportions and fit across the range. Poor grading is why a hoodie can fit beautifully in medium and look strangely short in XL, and it is a leading cause of returns in online fashion. It sits between sampling and production in the product development process; our garment sampling guide covers the stages around it.
Choose and Perfect Your Base Size
The base size (or sample size) is the size on which the pattern is developed, fitted and approved. Brands commonly choose a size in the middle of their range, such as a medium for menswear and unisex streetwear, or a UK 10–12 for womenswear, depending on the customer. Fitting and refining the base size on a model or dress form, and approving it through the fit-sample stage, is critical: any error in the base size will be multiplied across every other size when it is graded.
Before you grade, make sure the base size is signed off, including the measurements, the construction and the fabric. Fabric matters because a stretchy jersey and a rigid woven can need quite different patterns, and shrinkage affects finished measurements. See hoodie fabric and T-shirt fabric guides for how weight and fibre influence fit.
Points of Measure (POMs)
A size chart is a table of points of measure: the specific places on a garment where it is measured, each with a defined method. Using the same method every time is vital, because a “chest” measured differently by the brand and the factory produces garments that do not match the specification. For a T-shirt or hoodie, typical points of measure include:
- Chest width (usually measured flat, 2.5 cm below the armhole, then doubled for circumference).
- Body length from the high point shoulder to the hem.
- Shoulder width from shoulder seam to shoulder seam.
- Sleeve length from shoulder point (or centre back) to cuff edge.
- Sleeve opening / cuff width and hem opening.
- Neck width and front and back neck drop.
- Hood height and width and pocket size and position for hoodies.
For trousers and jeans the list differs: waist, hip, front and back rise, thigh, knee and leg opening, inseam and outseam. Whatever the garment, document each measurement with a diagram and a short description of how and where to take it.
Grade Rules: The Increments Between Sizes
Grade rules specify how much each point of measure changes from one size to the next. The numbers are a design decision, not a universal standard, and they depend on the customer, the market and the garment. As a general illustration only, many menswear and unisex tops grade chest circumference in steps of roughly 4 to 6 cm between sizes, with body length and sleeve length changing by smaller increments of around 1 to 2 cm. Brands serving different customers or fits (slim, regular, oversized) set different increments.
It helps to remember that bodies do not grow proportionally in every direction. A chest measurement increases by more per size than the shoulder width or the neck opening, and sleeve length may change only a little. A simple “scale everything evenly” approach produces a garment that looks wrong at the extremes of the range. Thoughtful grade rules, ideally based on size surveys or on your own fit data, keep the garment looking and feeling right in every size.
An Illustrative Size Chart
The table below is an example format, showing flat measurements for a unisex oversized T-shirt with an illustrative chest grade of 5 cm per size. It is not a recommended size standard.
| Point of measure (cm, flat) | S | M | L | XL | Grade |
|---|---|---|---|---|---|
| Chest width (2.5 cm below armhole) | 56 | 58.5 | 61 | 63.5 | +2.5 |
| Body length (HPS to hem) | 70 | 72 | 74 | 76 | +2 |
| Shoulder width | 50 | 52 | 54 | 56 | +2 |
| Sleeve length | 22 | 23 | 24 | 25 | +1 |
Notice that the chest width grades by 2.5 cm flat, which is 5 cm in circumference. Many size-chart errors come from mixing flat and circumference measurements, so always label which one you mean.
Measurement Tolerances
No factory can produce garments with perfectly identical measurements, so every point of measure should have an agreed tolerance: the amount by which the finished garment may differ from the specification and still be acceptable. A common starting point for casual tops is around ±1 cm on chest and body length and slightly tighter or looser on other points, depending on the garment and fabric stretch. Knits and heavily washed garments often need wider tolerances than rigid wovens.
Tolerances are what an inspector checks against at AQL inspection: a garment outside tolerance is typically counted as a defect, so they need to be written into the specification and agreed with the factory before production.
Designing Grade Rules for Different Fits
The same size label can mean very different measurements depending on the fit you are designing, and your grade rules should reflect this. A slim fit uses small ease allowances and relatively tight increments, because the body measurement and the garment measurement are close, so a mistake of 1 or 2 cm is immediately noticeable. A regular fit allows more ease and is more forgiving. An oversized or boxy fit is usually designed by adding generous width and dropping the shoulder, so the garment’s chest measurement is much larger than the body it is made for, and fewer sizes (for example S to XL, or even one-size-fits-most) may be enough.
Decide the fit intent for each style before sampling and record it in the tech pack, together with the body measurements the pattern was drawn for and the ease allowance added. Without this record, future styles will drift in fit, and customers who liked the first hoodie will find the second one fits differently. Keeping a master size chart for each block (for example “regular tee block” and “oversized hoodie block”) and reusing it for new styles is the simplest way to keep your range consistent, and it also saves development cost, which matters when you are working with small first orders.
Testing Fit Before Bulk Production
Measurements on paper are not the same as fit on a person. Before bulk, approve a pre-production sample in the base size, and where budget allows, ask for the smallest and largest sizes too. Try them on fit models or on a few friendly customers with a range of body shapes and ask specific questions: does the garment ride up when you raise your arms, are the sleeves long enough, does the hood sit comfortably, is the neck opening comfortable? Take photographs and measure the garments again after washing. The feedback is far cheaper to act on before the order is cut than after 500 pieces have been delivered.
Common Grading and Size Chart Mistakes
- Grading from an unapproved base size. Errors multiply across the range.
- Ignoring fabric shrinkage. Garments measure correctly before washing and too small after; build the shrinkage allowance into the pattern.
- Mixing flat and circumference measurements. Always state which one is used.
- Different measuring methods in the brand’s and factory’s documents. Include diagrams.
- Uniform grading. Scaling every measurement equally distorts proportions.
- No fit review of the extremes. Check the smallest and largest sizes on real bodies, not only the base size.
- A website size guide that differs from the factory spec, producing returns despite correct production.
Publishing a Customer Size Guide
Customers do not read tech packs; they read your website’s size guide. Publish finished garment measurements (often in both centimetres and inches), explain how to measure a favourite garment at home, and note the fit (slim, regular or oversized) and the model’s height and size. Clear size information is one of the most effective ways to reduce returns, which protects the margin you worked to build in your pricing.
Where Grading Fits in the Tech Pack
Your tech pack should contain the base-size spec, the points of measure with diagrams, the grade rules and the tolerances. When working with a factory, send these as a single, version-controlled document and have the factory return the measurement table for each sample. If you are starting from scratch, our guide to starting a clothing brand explains where to put development time and budget. Many brands also start by taking measurements from a garment they already like that fits well and using it as a reference.
Grading and Fit Support at Ruhrose
Ruhrose helps brands translate their design into a graded, production-ready specification: fit samples, measurement review and size-set approval before bulk, on low minimums from 500 pieces per style and colour. If you already have a tech pack and size chart, we will work from it; if you do not, we can help you build one. Start a product enquiry to talk through your sizing.