This page teaches a cutting-room planner, mill contact or merchandiser how to calculate a fabric's usable width from its full loom width, its selvedge allowance and its shrinkage allowance. It is for anyone who checks a fabric roll's spec before a marker layout is planned, and no previous lesson is needed. This mainly teaches the product flow: usable width decides how many pattern pieces actually fit across a roll, and getting it wrong changes how a finished garment looks or fits.
At work, a cutting department cannot plan a marker against a roll's full stated width and assume every centimetre is usable. A roll's full width, off the loom, always includes width that cannot be cut, plus a further margin the fabric is expected to lose once washed or finished. Without this skill, a cutting department either loses fabric cutting into the unusable edge, or ships a garment that shrinks out of size after the first wash.
The two allowances taught here, selvedge and shrinkage, are standard textile facts, not a claim about any one company's fabric. This academy's cast has no fixed selvedge or shrinkage figure for either fixed order, so this lesson works a generic, clearly labelled illustrative example to teach the method itself, one a cutting department applies to whatever figures its own roll's spec states.
You need: No previous lesson. Lesson 3.1's method for calculating fabric consumption per piece is useful background but not required here.
By the end of this lesson you can:
Not covered here: how a marker itself is laid out across a fabric's usable width (a later fabric-calculations lesson), calculating a whole order's total fabric requirement (Lesson 3.4, next), converting fabric weight between GSM and oz/yd2 (Lesson 3.2).
| Term | Meaning |
|---|---|
| Selvedge | The tightly-woven edge strip where the weft yarn turns back; too dense and different in structure to use in a garment, subtracted from both edges of a fabric's full width. |
| Shrinkage allowance | An extra margin subtracted from a fabric's remaining width to account for the fabric shrinking after washing or finishing, so the finished garment still fits after that shrinkage has happened. |
| Full width | A fabric's whole width as it comes off the loom, stated on a spec sheet before any allowance is subtracted. |
| Usable width | The width actually available for pattern pieces once the selvedge and shrinkage allowances have both been subtracted from the full width. |
| Marker layout | The cutting layout that arranges a garment's pattern pieces on a length of fabric before cutting; it must fit inside the fabric's usable width, not its full width. |
| Weft | The yarn that runs across a woven fabric's width, turning back at each edge to form the selvedge. |
A fabric's full width, as it comes off the loom, is not all usable for cutting. A small strip at each edge, the selvedge, is where the weft yarn turns back to weave the next row; this strip is too dense and too different in structure from the rest of the fabric to use in a garment, so it is subtracted from both edges of the full width. What remains is then reduced by a shrinkage allowance, an extra margin subtracted because the fabric shrinks somewhat after its first wash or wet processing, so the finished garment still fits once that shrinkage has actually happened. Usable width equals full width, minus the selvedge on both edges, minus the shrinkage allowance applied to what is left. This calculation belongs on a live formula, on this course's fabric calculator, never as a typed final number.
| What can differ | The shapes you meet | Why it matters |
|---|---|---|
| Selvedge width | Commonly a narrow strip on each edge, but the exact figure varies by loom and fabric; always stated on the roll's own spec, never assumed | Subtracting the wrong selvedge width either wastes usable fabric or lets a marker land in the unusable strip |
| Shrinkage allowance | A percentage applied to the remaining width after selvedge is removed; the exact rate depends on the fabric's fibre content and finishing process | Too small an allowance risks a finished garment shrinking out of size after the customer's first wash |
| Full width vs usable width | A spec sheet states the full loom width; the usable width for cutting is always somewhat less | Planning a marker against the full width overstates how many pattern pieces actually fit |
| No fixed cast figure | Neither Order A's knit fabric nor Order B's denim has a fixed selvedge or shrinkage percentage in the master cast | This lesson uses a clearly labelled illustrative example instead of inventing a specific claim about either order |
| Related product families | Home-textile bedding and terry towels also carry selvedge and shrinkage allowances on their own woven widths, following the same two-step method | The same calculation reappears outside apparel wherever a woven fabric is cut to a marker |
Suez Denim, the denim mill, supplies a new roll of denim for a domestic, Make to Stock reorder of Order B, the five-pocket jeans. The roll is not tied to one single confirmed buyer order; Delta Garments' cutting department is restocking its own running domestic production against its own forecast, so it needs the roll's usable width confirmed correctly before committing cutting time and fabric to a marker layout. This is a domestic, mill-side scenario: Suez Denim states the roll's full width, selvedge and shrinkage allowance on its own spec sheet, and Delta Garments' cutting department must calculate the usable width from that spec before it plans anything.
The worked numberThis example is clearly labelled as illustrative: it uses a generic 150 cm full width, not a claim about Order B's own denim width, since neither Order A nor Order B has a fixed selvedge or shrinkage figure in the master cast.
Subtracting the selvedge first, 1 cm from each of the two edges, 2 cm total, from the 150 cm full width leaves 148 cm. Applying the 3% shrinkage allowance to that 148 cm, 148 multiplied by 0.97, gives about 143.6 cm of usable width, worked as a live formula on this course's fabric calculator rather than typed in by hand.
A common mistake is planning a marker layout against the 150 cm full width stated on a roll's spec, instead of the roughly 143.6 cm usable width that remains once selvedge and shrinkage have both been subtracted. A cutting department that does this risks pattern pieces landing partly in the unusable selvedge strip, wasting cut fabric, or a finished garment shrinking out of its intended size after the customer's first wash, since the shrinkage allowance was never actually applied to the layout. Either mistake surfaces only after cutting has already happened, when the fabric and the cutting time are both already spent.
This lesson shows how to work out how much of a fabric's width can actually be used for cutting. A fabric's full width, as it comes off the loom, includes a narrow strip at each edge that cannot be used in a garment, because that is where the crossing threads turn back. Taking that strip off both edges leaves a smaller width. Fabric also shrinks a little once it is washed or finished, so a further small percentage is taken off the remaining width to make sure the finished garment still fits after that shrinking happens. What is left after both of these steps is the usable width, the real amount of fabric a cutting layout can actually use.
Suez Denim supplies a new denim roll for a domestic, Make to Stock reorder of Order B at Delta Garments. Before the cutting department commits fabric and cutting time to a marker layout, it must confirm the roll's usable width from the spec.
What is the usable width for the marker layout? Decide before you open the answer.
About 143.6 cm is the usable width. Subtracting the selvedge, 1 cm on each of the two edges, 2 cm total, from the 150 cm full width leaves 148 cm. Applying the 3% shrinkage allowance to that 148 cm, 148 multiplied by 0.97, gives about 143.6 cm. Cutting a marker against the full 150 cm width instead would risk pattern pieces landing in the selvedge strip, or the finished garment shrinking undersized after the customer's first wash, since the shrinkage allowance was never applied.
Cutting against a fabric's full width instead of its usable width carries a real cost, framed here qualitatively since this illustrative example attaches no order-specific dollar figure to it. If Delta Garments' cutting department planned a marker against the full 150 cm width instead of the roughly 143.6 cm usable width, pattern pieces could land partly in the unusable selvedge strip, wasting the fabric already cut and the cutting time spent on it. If the shrinkage allowance was ignored instead, the finished garment could shrink out of its intended size after the customer's first wash, risking a returned or rejected batch on a domestic reorder the factory planned to sell from its own stock. Both risks are exactly what this lesson's two-step calculation, subtract the selvedge then apply the shrinkage allowance, is designed to prevent before any fabric is cut.
This course's Fabric calculator holds a live-formula row for turning a fabric's full width into its usable width, the same two-step calculation worked through in this lesson. Enter the full width, selvedge allowance and shrinkage percentage in the yellow input cells, and the white result cell recalculates the usable width automatically.
| Question | This lesson's illustrative example | Your fabric roll |
|---|---|---|
| Full width | 150 cm | |
| Selvedge (both edges) | 2 cm (1 cm each edge) | |
| Remaining width | 148 cm | |
| Shrinkage allowance | 3% | |
| Usable width | About 143.6 cm |
Download the Fabric calculator from the course page and enter your own fabric roll's real full width, selvedge and shrinkage figures in the third column.
1. What is a fabric's selvedge?
2. Why is a shrinkage allowance subtracted from a fabric's usable width?
3. A fabric roll's spec states a 200 cm full width, 1.5 cm selvedge on each edge, and a 4% shrinkage allowance. What is the approximate usable width?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Selvedge | الحاشية (السلفدج) | Lisière | Kenar (selvedge) | The tightly-woven edge strip where the weft yarn turns back; too dense and different in structure to use in a garment, subtracted from both edges of the full width. |
| Shrinkage allowance | هامش الانكماش | Marge de retrait (rétrécissement) | Çekme payı | An extra margin subtracted to account for the fabric shrinking after washing or finishing, so the finished garment still fits after the fabric's own shrinkage has occurred. |
| Full width | العرض الكامل | Largeur totale | Tam genişlik | A fabric's whole width as it comes off the loom, stated on a spec sheet before any allowance is subtracted. |
| Usable width | العرض القابل للاستخدام | Largeur utile | Kullanılabilir genişlik | The width actually available for pattern pieces once the selvedge and shrinkage allowances have both been subtracted from the full width. |
| Marker layout | تخطيط الماركر | Plan de placement (marker) | Marker düzeni | The cutting layout that arranges a garment's pattern pieces on a length of fabric before cutting; it must fit inside the fabric's usable width, not its full width. |
| Weft | خيط اللحمة | Trame | Atkı ipliği | The yarn that runs across a woven fabric's width, turning back at each edge to form the selvedge. |
You now know how to turn a fabric's full width into its usable width. The next lesson uses this course's fabric calculator to work out the total fabric a whole order needs once consumption and width are both confirmed. Back to the course map