# Fabric width converter

When a pattern specifies a length at one fabric width and your fabric is a different width, multiply the pattern length by the pattern width and divide by your width: 3 metres of 115 cm fabric becomes 2.3 metres of 150 cm fabric. This is an area equivalence, and it holds only for plain, non-directional fabric whose pattern pieces can be rearranged freely. A one-way design, a nap, or any single piece wider than the narrower roll breaks it — the converter below flags those cases rather than printing a figure you cannot rely on.

Source: https://fabricmeasure.com/conversions/fabric-width-converter/
Last updated: 2026-08-20 (method v1)
Published by FabricMeasure.

---

## The formula

```
newLength = patternLength x patternWidth / yourWidth
```

Then round up to your shop cutting increment.

This is an AREA equivalence and holds only for plain, non-directional fabric whose
pieces can be rearranged freely. It is wrong when:

- any single pattern piece is wider than the narrower roll (no length fixes this);
- the fabric is directional or has a nap (pieces cannot be rotated to nest);
- you are moving to a NARROWER roll (pieces that sat side by side may no longer fit).

## Nominal roll widths and what they actually measure

| Sold as | Also labelled | Exact |
| --- | --- | --- |
| 36 in | 90 cm | 91.4 cm |
| 44 in | 112 cm | 111.8 cm |
| 45 in | 115 cm | 114.3 cm |
| 54 in | 137 cm | 137.2 cm |
| 55 in | 140 cm | 139.7 cm |
| 60 in | 150 cm | 152.4 cm |
| 108 in | 274 cm | 274.3 cm |

54 inches is 137.16 cm, not 140. The trade uses the labels interchangeably.

## Common questions

### Is 54 inches the same as 140 cm?

No. 54 inches is 137.16 cm, not 140. The trade uses the two labels interchangeably for furnishing fabric, but they are nearly 3 cm apart — enough to matter when you are joining widths to a fixed finished size.

### When does the conversion stop working?

When the pieces cannot be rearranged. If any single pattern piece is wider than the narrower roll it simply will not fit at any length. A directional print or a fabric with a nap also breaks it, because pieces can no longer be rotated to nest together.

### Should I add extra on top of the converted figure?

Yes, when going to a narrower fabric. The area maths assumes pieces that used to sit side by side still do, and on a narrower roll they often cannot — so the honest answer is the converted figure plus one extra pattern-piece length as insurance.

## Related tools

- [Curtain fabric calculator](https://fabricmeasure.com/calculators/curtain-fabric-calculator/): Track width, drop, fullness and pattern repeat in; metres or yards to buy out, with every allowance adjustable.
- [Fabric yardage calculator](https://fabricmeasure.com/calculators/fabric-yardage-calculator/): Piece size, how many, roll width — the length to buy, and the strip you pay for but never cut.
- [Fabric GSM calculator](https://fabricmeasure.com/conversions/fabric-gsm-calculator/): g/m², oz/yd², running-yard ounces and momme — plus the weight of an unlabelled fabric from a swatch.
- [Curtain fullness calculator](https://fabricmeasure.com/calculators/curtain-fullness-calculator/): How many widths each curtain needs at the fullness you want — and what whole widths really gather to.
- [Pattern repeat calculator](https://fabricmeasure.com/calculators/pattern-repeat-calculator/): The cut length a repeat forces, what is trimmed from every piece, and what matching the design costs.
- [Yards to metres](https://fabricmeasure.com/conversions/yards-to-metres/): Convert a pattern written in yards to metres, with the common cut lengths tabulated.