Building a Size Chart for Your First Collection: A Factory Walkthrough

"Just make it in S through XL" is not a size chart — it is a request for the factory to guess. And when a factory guesses, the garment fits like the factory's assumptions, not like your brand. The good news: building a real size chart is a two-hour job with a tape measure, and you only have to do it properly once per silhouette. Here is how we walk first-time brands through it.

What a size chart actually is

A size chart is a table: one row per measurement point, one column per size, numbers in centimeters (preferred in production) or inches. For a hoodie, the core points are:

• Chest width — armpit to armpit, laid flat
• Body length — highest point of shoulder to hem
• Shoulder width — seam to seam across the back (or "dropped X cm" for drop-shoulder builds)
• Sleeve length — shoulder seam to cuff end
• Hem and cuff rib height, hood height/width for hooded styles
• Sleeve opening, neck width as secondary points

Bottoms swap in waist (relaxed and extended), hip, thigh, rise, inseam and leg opening. None of this requires software — a spreadsheet is the industry standard.

Here is what the format looks like for a hoodie. This is an illustrative example with placeholder numbers, not a spec to copy:

Size	Chest width (cm)	Body length (cm)	Tolerance
S	58	68	±1.5 cm
M	60	70	±1.5 cm
L	62	72	±1.5 cm
XL	64	74	±1.5 cm

The example uses a consistent 2 cm grade step to keep the pattern visible; real charts vary the step by measurement point, as covered below.

The reference-garment method (how everyone actually does it)

Almost nobody designs a size chart from scratch. The working method:

1. Find the garment that already fits the way you want — from your closet, a competitor, anywhere. This is your fit reference.
2. Measure it flat, every point above, and write down the numbers. That is your base size (usually M or L in streetwear).
3. Decide what to change. "This, but 4 cm longer in the body and a wider sleeve opening" is a perfect brief. The reference plus deltas communicates fit better than any adjective.
4. Send the numbers AND the reference photos. If you can ship us the physical reference garment, better still — we can measure it ourselves and flag anything your tape missed.

This is also the honest answer to "do I need a tech pack?" — for fit, a measured reference garment does the job. We build the rest of the spec with you during design review.

Grading: how one size becomes five

Grading is the rule set for how measurements step between sizes — for example, chest width +5 cm per size, body length +2 cm, sleeve +1.5 cm. Two things matter:

Steps are not uniform across measurement points. Chest grows faster than sleeve length; hood dimensions barely move. Standard grading rules exist per garment type, and this is genuinely a place to lean on your factory — we apply streetwear-appropriate grade rules and show you the full chart before pattern making.

Oversized fits change grading logic. When a base fit is already generous, aggressive grading makes XL enormous. Modern streetwear often uses tighter grade steps than classic garments precisely because the base is oversized. If your brand sells mostly two or three sizes (most young brands do), say so — the grade can prioritize the sizes that sell.

Tolerance: the honest number nobody puts on Instagram

Sewn garments are made by humans from fabric that moves. Every production size chart carries a tolerance band — commonly around ±1 to ±2 cm depending on the measurement point. This is industry physics, not corner-cutting. What you should expect from a factory: the tolerance stated per measurement on the spec, and the sample measured against it in writing. That measured sample — not the abstract chart — becomes the production standard you approve.

Three mistakes we see monthly

1. Copying a US retail chart for an oversized streetwear fit. Retail body-measurement charts and flat garment measurements are different documents. Production uses flat garment measurements.
2. Skipping the wash consideration. Fabric relaxes and shrinks; heavy washes change measurements. The pattern is built with shrinkage allowances for the specified fabric and wash — one more reason fabric weight, wash and fit are decided together, and why we check measurements after the sample's first wash.
3. Six sizes for a first drop. How sizes can be distributed inside the confirmed order depends on the design, colorway, and production plan. Every size you add also concentrates inventory risk on the sizes you guess wrong. Most first drops do well with three or four sizes weighted toward M/L/XL.

What to send us

A measured reference garment (or its flat measurements), photos, your target changes, and how many sizes you want. From that, design review returns a full graded chart for approval — usually alongside the formal quote after sufficient project details are reviewed — and the sample in 10-15 working days proves it on real fabric. Fit is locked on the physical sample, where you can measure it against the chart yourself: the sample approval checklist covers exactly how.

FAQ

Do I need different charts for hoodies and tees? Yes — every silhouette gets its own chart, because construction and ease differ. But the reference-garment method is the same two-hour process each time.

Can you copy the fit of a garment I send you? Yes, that is the most reliable brief there is. We measure it, build the chart, and you confirm the deltas you want.

What if my sample measures inside tolerance but feels wrong? Then the spec was wrong, not the sewing — and that is precisely what the sample stage exists to catch. We adjust the pattern and re-check. Changing a number on a chart is free; discovering it at bulk is not.

Centimeters or inches? Production worldwide runs in centimeters; send inches if that is what you have and we convert. Just never mix the two in one document.