How do you grade clothing sizes from one sample?
Approve a base-size garment, define how each measurement changes across the size range, and check physical samples in the agreed sizes before releasing bulk. A good medium sample only establishes one size. It does not prove that the smallest and largest sizes preserve the intended fit.
Keep three decisions separate: the target customer’s body measurements, the finished garment specification, and the acceptable manufacturing variation around that specification. A size label such as M or XL cannot replace those records.
Separate body size, garment size and manufacturing tolerance
ISO 8559-2:2025 describes a size-designation system based on body measurements. That is a different purpose from a factory’s finished-garment measurement sheet. Use both concepts clearly in your brief.
| Record | What it describes | Buyer check |
|---|---|---|
| Body measurement table | The people a size is intended to fit | Identify the intended customer group and measurement method. |
| Finished garment specification | The actual garment dimensions, including the intended silhouette | State flat width or circumference, units, measurement points and garment condition. |
| Grade rule | The planned change between sizes | Define it for each measurement and each size interval. |
| Measurement tolerance | The permitted deviation from a size’s target | Agree limits for each point; do not use the grade increment as a tolerance. |
For example, a flat half-chest width of 60 cm is not a 60 cm body chest measurement. Doubling a flat width gives a simple garment-circumference approximation; it does not establish who the garment will fit. Construction, stretch and the intended wearing ease still need review.
Approve the base size before extending the range
Choose a development size that represents your target customer and available fit model or form. Medium is an option, not a universal requirement. Record the model or form’s relevant measurements without publishing personal identifying information.
Review the base garment’s balance, movement, fabric and styling proportions. For a dropped-shoulder hoodie, a chest measurement alone cannot describe shoulder position, sleeve reach, armhole shape or hood balance. Use the boxy, oversized and cropped fit guide to define the silhouette first.
If the base sample changes, ask which size-chart values and pattern pieces must change with it. Carrying an old grade table forward after a major fit revision can leave the remaining sizes based on an obsolete starting point.
A worked example: grade increments are not tolerances
Lectra defines grading as adapting a base pattern into multiple sizes while preserving the garment’s intended fit and proportions. The change need not be the same for chest, length and sleeve, or across every size interval.
Illustrative arithmetic only: the values below are invented to explain a chart. They are not a production-ready T-shirt specification, a universal size standard or Wincome Apparel’s default tolerances.
| Point of measure, cm | S | M | L | Change per step | Example tolerance |
|---|---|---|---|---|---|
| Half chest, flat | 57 | 60 | 63 | +3 | ±1.0 |
| Body length, defined start and end points | 68 | 70 | 72 | +2 | ±1.0 |
| Sleeve length, shoulder seam to sleeve edge | 23.5 | 24 | 24.5 | +0.5 | ±0.5 |
In this example, size M half chest has a 60 cm target and a 59–61 cm permitted range. The 3 cm grade step defines the next size; it does not permit size M to vary by 3 cm. A 61.5 cm M sample falls outside this illustrative limit, even though it is below the L target.
Ask the patternmaker to review the intended size range as a whole. Avoid applying one percentage increase or one fixed increment to every measurement. The pattern must still join correctly, and details such as pockets, artwork and neck openings need their own size decisions.
What should a size-set review include?
A size set is a group of samples used to review the size range. Agree whether you need every size or selected sizes; do not treat a universal sample count as sufficient for every product. A new block, an extended range or unresolved fit concerns can justify a broader review.
- Identify the samples. Record style, color, size, material, finish, pattern version and sample date. Mark substitutes that limit what can be approved.
- Measure consistently. Use the same illustrated points of measure, units and garment condition. State whether elastic areas are relaxed or stretched and how they are handled.
- Check fit across the agreed range. Review movement and proportions on suitable models or forms. Measurements alone cannot show every fit problem.
- Review linked details. Check sleeve and shoulder balance, pocket access, neck or hood opening, artwork placement and label-size accuracy.
- Close the differences. For each issue, name the affected sizes, correction, responsible person and required recheck before approval.
For washed garments, distinguish the finished production-wash condition from subsequent home-laundering checks. Specify when each measurement is taken and the agreed washing and drying method. A measurement taken before finishing is not interchangeable with one taken afterward.
Use one measurement and correction record
Attach a worksheet to the current tech pack with these columns: style and sample ID; size; point of measure and method; target; lower and upper limit; actual result; difference; decision; correction owner; recheck date.
Example comment: “M half chest measures 61.5 cm; target 60 cm; agreed range 59–61 cm. Remeasure using the approved method, then investigate the pattern or construction if confirmed. Review the affected sizes before approval.” This connects an observation to a defined requirement without assuming the cause.
If a size meets its measurements but does not fit as intended, revisit the design or grade rule. If it misses a well-defined target, investigate execution and remeasure. Changing the tolerance simply to accept a failed sample hides the original requirement.
Keep the accepted chart, pattern revision and sample decisions together. The pre-production approval checklist covers the broader garment approval, and the bulk inspection checklist carries those requirements into the production lot. Size-set approval does not inspect every bulk unit.
What to send for a size-grading review
- Product type and intended fit
- Target customer and planned size range
- Base sample and current measurement chart
- Measurement diagrams and units
- Fabric, stretch and finishing details
- Proposed grade rules and open questions
- Tolerances by measurement point
- Required sample sizes and approval owner
For custom T-shirts or custom hoodies, Wincome Apparel can review the brief and coordinate the agreed development route through authorized manufacturing partners. Sampling scope, feasibility, pricing and timing are confirmed for each order.
Sources and scope
Technical references checked September 27, 2026: ISO 8559-2:2025, public abstract for body-based size designation, and Lectra’s product-development glossary for grading and fit development. The worksheet, arithmetic example and buyer review sequence are Wincome Apparel’s explanatory guidance, not excerpts from a standard or evidence of a completed customer order.