How fit guidance supports sourcing decisions
A fit guide helps buyers ask better questions before quotation and sample review.
Clear fit terminology helps buyers compare suppliers and prepare more specific sourcing questions.
How to read a leggings size specification
A leggings specification is built around one base size, usually the middle of the range. The measurement points that matter are waist, hip, front rise, inseam, leg opening and waistband height, recorded on the approved sample. Two specifications can look similar and still mean different things: one may list flat measurements taken across a folded garment, while the other lists full body circumferences. A flat waist figure is roughly half the circumference, so mixing the two systems doubles or halves a size without anyone noticing. Every specification should state which system it uses, point by point.
Tolerances belong in the same document. A measurement without an agreed tolerance cannot be checked at inspection, so buyers normally agree an allowable plus/minus range for each point before production, and the bulk inspection then measures against the approved sample and that written tolerance.
Grading: how sizes step up and down
Grading is the rule that turns the base size into the rest of the range. For women's leggings, a common market reference is a 2.0–2.5 cm step on waist and hip circumference per size, with smaller steps on length points such as inseam, which some ranges keep constant across sizes. These figures are a starting reference only: the grading rule for an order is the one confirmed with the pattern maker and recorded with the approved sample. Plus-size ranges usually grade with larger, less linear steps and should be agreed as their own rule instead of being extrapolated from the standard range.
Never grade from a photograph or a product name. Two styles described as high-waist can carry different rises, and the same size label can sit differently across fabrics with different stretch and recovery.
Fit types and compression levels
Fit describes the silhouette — fitted, regular or relaxed — while compression describes how firmly the fabric holds the body. The standard catalog specification pairs a 75% nylon / 25% spandex fabric at approximately 220 GSM with a medium compression target, which suits most yoga and studio ranges. Light compression feels softer for lounge and maternity-adjacent lines, while high compression is usually chosen for training collections and needs a firmer fabric and a wear test, because a size that fits in medium compression can feel a full size smaller in high compression.
When a collection mixes compression levels, fit-check each level separately at sampling. Approving one level does not clear the others.
The fit approval workflow before bulk production
A reliable sequence is: measure the sample against the specification, wear-test it through standing, bending, squat and lunge movements, wash it and measure again, then record the approved figures and sign the sample off in writing. The written record — fabric code, color, base-size measurements, grading rule, tolerances and logo and label positions — is what bulk production and final inspection are checked against.
Size planning belongs to the same step. Confirm the size ratio for the bulk order from your own sales data or market plan, and state it in the order, instead of accepting a default ratio that may leave you long on slow sizes and short on the sizes your customers actually buy.
Common fit problems and where they start
Most fit complaints trace back to three points: a waistband that rolls or digs because its height and elastic recovery were never wear-tested, opacity that was only checked on a dark base-size sample, and a size range graded from another supplier's chart without a sample in the actual fabric. All three are cheap to catch at sample stage and expensive to fix after bulk production, which is why this guide puts measurement, movement and wash checks before the order rather than after it.