Turn one fitted base measurement into a full graded size set: enter the base, choose a grade increment per size, and set how many sizes to add above and below. The grade maths is exact and uniform — real production grade rules can taper at the extremes, so confirm your graded spec at sampling.
⚠️ Uniform grade — exact maths, indicative rule. The calculation is exact: each size is the base plus a whole number of grade steps. But it applies one uniform increment across the whole range. Real production grade rules are often not perfectly linear — many brands taper the step at the size extremes and use a different increment for each point of measure (chest, length, sleeve, neck). Treat this as a first draft grade rule, then confirm the graded spec against a fit sample before bulk. Units are yours: work in cm or inches, as long as the base and the increment use the same unit.
Grading derives every size from a single fitted base by adding or subtracting a constant grade increment. Sample and approve the base fit first, then let the grade rule generate the rest.
Chest grades faster than length; sleeve and neck grade slower still. Run this tool once per point of measure, giving each its own increment — that's how a real grade sheet is built.
A linear grade is the honest first pass. Production rules often taper the step at XS and XXL so the extremes don't drift. Adjust the break points once you have fit samples.
Each size you grade to is its own 250-piece minimum on the machine. At Kiwi Giyim the 250-piece minimum is per colour and per size, so grading out from S–L to XS–XXL turns three 250-piece runs into five. Plan the run after you set the grade.
Every graded size is the base plus a whole number of steps. Step 0 is the base, negative steps are smaller sizes, positive steps are larger:
measurement(step) = base + step × increment step = −(sizes below) … 0 … +(sizes above) Worked example: base chest 96, increment 4, 2 sizes below and 2 above gives steps −2 to +2 → 88, 92, 96, 100, 104. No estimation, no rounding drift beyond display.
Common planning starting points for a regular adult knitwear range — not a standard. Confirm each against your fit sample:
| Point of measure | Typical grade / size | Notes |
|---|---|---|
| Chest / bust (½) | 4–5 cm (≈ 1.5–2 in) | the primary grade; 5 cm for a fuller range |
| Body length | 1.5–2.5 cm | grades slower than width |
| Sleeve length | 1–1.5 cm | from centre-back or shoulder point |
| Shoulder width | ≈ 1 cm | small, steady step |
| Neck width | 0.5–1 cm | often flattened at the extremes |
Building the full spec? Pair the grade with the knitwear cost calculator and the yarn count converter, then split the order across sizes. New to sourcing? Start with our knitwear manufacturer overview.
Size grading is how every size in a range is derived from one base (sample) size: you take the fitted measurements of the base and add or subtract a fixed grade increment at each point of measure to step up and down the range. The base is the size you fit and sample first, and the graded sizes are calculated from it — so a clean grade rule is what lets a factory knit S through XL from a single approved fit.
As an indicative starting point, chest or bust often grades around 4 cm (roughly 1.5 in) between neighbouring sizes for a regular range, or about 5 cm for a fuller one. Other points of measure take their own smaller steps — body length around 2 cm, sleeve length around 1 to 1.5 cm, neck and shoulder under 1 cm. These are planning defaults, not a standard; confirm the real increments against your fit sample.
This tool applies a single uniform increment — a linear grade — which is the honest way to draft a first spec. In production, grade rules are often not perfectly uniform: many brands taper the step at the extremes (XS and XXL) and vary it by point of measure. Use the uniform grade as a starting draft, then adjust the break points from fit samples before bulk.
The base is the size you fit first and grade out from. Many brands sample the middle of their range — M for womenswear, L for menswear — so any grading error stays smallest at the extremes. At Kiwi Giyim we read your graded spec against a sampling swatch before bulk, and our 250-piece minimum is per colour and per size — each size is knitted from its own machine programme, so grading out to more sizes adds 250-piece runs rather than dividing one.
Send your tech pack with the graded spec from this tool and we'll reply within one business day with pricing, a sample timeline and an honest feasibility read on your knit.