Fabric Width Conversion Calculator
Convert original yardage to a new fabric width, then account for usable selvedge loss, piece count, repeat matching, nap direction, seam allowance, waste, and bolt rounding.
Load a common fabric swap, then tune the inputs for your exact fabric label width and usable cut width.
Conversion breakdown
Formula used
Equivalent length = original length x original usable width / new usable width.
Allowances are added after the width conversion so the base area stays clear.
Usable width
Usable width subtracts both selvedges.
A 54 in bolt with 0.75 in lost per side gives 52.5 in of planning width.
Repeat matching
Each piece can round up to the next full repeat.
Large repeats add length fastest when the project has many separate pieces.
Bolt conversion
The final result rounds to common store cuts.
Use 1/4 yard for most fabric counters or full yard for roll ordering.
| Width swap | Starting length | Width-only conversion | Common use |
|---|---|---|---|
| 45 in to 54 in | 4 yd | 3.33 yd | Upholstery, pillows, slip seats |
| 54 in to 45 in | 4 yd | 4.80 yd | Decor fabric swapped to narrower cotton |
| 54 in to 60 in | 5 yd | 4.50 yd | Drapery and wide sheers |
| 44 in to 108 in | 8 yd | 3.26 yd | Quilting cotton to wide backing |
| 60 in to 45 in | 3 yd | 4.00 yd | Canvas or apparel to narrower goods |
| Fabric family | Label width | Typical usable width | Selvedge note |
|---|---|---|---|
| Quilting cotton | 44 to 45 in | 42 to 43.5 in | Trim both printed edges before piecing |
| Home decor cotton | 54 in | 52 to 53 in | Check woven edge thickness |
| Drapery fabric | 54 to 60 in | 52.5 to 58.5 in | Directional prints may need one-way cuts |
| Fashion fabric | 55 to 60 in | 53 to 58.5 in | Knits can curl at the edge |
| Wide quilt backing | 104 to 118 in | 102 to 116 in | Square the cut ends before loading |
| Pattern repeat | Added per piece | Best used for | Planning note |
|---|---|---|---|
| 0 in | 0 in | Solids, small textures | No repeat matching needed |
| 4 to 8 in | Up to one repeat | Small prints, ticking stripes | Usually modest extra length |
| 12 to 18 in | Up to one repeat | Florals, medallions, checks | Match visible panels first |
| 24 in or more | Up to one repeat | Large drapery motifs | Piece count strongly affects yardage |
| Order unit | Increment | Equivalent | When to use |
|---|---|---|---|
| Fine cut | 1/8 yd | 4.5 in | Small projects and trim pieces |
| Standard cut | 1/4 yd | 9 in | Most fabric counter purchases |
| Generous cut | 1/2 yd | 18 in | Directional prints and home textiles |
| Roll planning | 1 yd | 36 in | Large bolts, drapery, upholstery runs |
When changing the width of a fabric, the yardage required for the project must be recalculated. Many people assumes that if a fabric is wider, it will require less yardage for the project. However, this isnt always the case with fabrics of different widths.
Furthermore, the width of one fabric cannot be divided by the width of another to determine how many yard of the other fabric will be required for the project. These factors that must be accounted for when changing the width of the fabric include the usable width of the fabric, the pattern repeat of the fabric, the nap of the fabric, and the necessary seam allowance for the project. The first factor to consider when calculating the yardage required for a sewing project is the usable width of the fabric.
How to figure out how much fabric you need when the width changes
Every bolt of fabric has selvedges on both ends of the bolt. These selvedges is created to prevent the fabric from fraying. The selvedges also often contain text from the fabric manufacturer, pinholes, or stripes on the fabric that are not part of the design of the fabric.
Because these selvedges are not part of the usable width of the design, you must trim them from the fabric prior to sewing. Therefore, yardage cannot be calculated with the total width of the fabric bolt but with the usable width of the design of the fabric. The second factor to consider is the pattern repeat of the fabric.
If the fabric contains a large design, such as a floral motif or another geometric design, the pattern must be accounted for when calculating the yardage of the fabric. Because the design must continue at the seam of the fabric, the pattern piece cannot be placed on the fabric in any way that will prevent the design from correctly continuing at the seam. Therefore, each pattern piece will require additional inches of length to account for the pattern repeat of the design, and fabrics with a large pattern repeat will require more yardage then fabrics without a pattern repeat.
The third factor to consider is the nap of the fabric. Fabrics such as velvet and corduroy have a nap to the fabric. The nap is the way in which the fabric reflects light on the surface of the material.
If one pattern piece of a design is rotated in relation to the other pattern pieces of that design, it will appear to be a different color because of the difference in the way that it reflects light. Therefore, all pattern pieces of a project must be laid in the same direction on the fabric so that the design appears to be the same in all area of the project. Consequently, because of the need to lay all of the pattern pieces of a project in the same direction, some fabrics with a nap will make it impossible to nest the pattern pieces as close as with fabrics without a nap.
The fourth and final factor to consider when determining the yardage of the fabric is the seam allowances and waste of the fabric. Every pattern piece requires a seam allowance to join the pieces of the project. Furthermore, the fabric may shrink when washed, and the fabric may not be perfectly even on both ends of the bolt.
To account for this, many sewing professional add a waste buffer of ten percent to the total amount of yardage of the fabric to allow for potential shrinkage or crooked edge of the fabric. By doing so, there is a betterer chance that there will be enough fabric to complete the project rather than running out of fabric while sewing. Finally, the total yardage of the project must be rounded to the nearest increment in which the stores sell fabric.
Most fabric stores sell fabric in increments of a quarter of a yard or in halves of a yard. If the yardage of the project is calculated to an amount like 3.26 yards, the store may not cut the fabric to this measurement. Therefore, the yardage must be rounded up to the nearest quarter of a yard or half yard to make it easier for the individual purchasing the fabric to recieve the ordered yardage for the project.
By rounding the total amount of yards of fabric that are required for a project to the nearest increment, it can be ensured that there will be enough fabric to account for all of the factor that must be considered when altering the width of the fabric. Furthermore, if all of these factor are accounted for, the amount of yardage will be the correct amount of fabric required for the project.
