Fabric Width & Yardage — How to Calculate Exactly How Much to Buy
You've read the pattern. It says "2 yards of 45-inch fabric." You go to the store and find a fabric you love — but the bolt says 57 inches wide. Do you still buy 2 yards? Or can you get away with less?
This is the single most common "did I buy enough?" mistake in sewing, and it comes down to one number on the bolt: fabric width.
Width is the distance from one selvage to the other — the finished, usable edge to edge. It is not the same as the printed bolt width you might see online (that often includes the selvages, which you cut off). And it changes how much length you need, sometimes by a lot.
Here's the full picture, with real numbers and real fabrics you can actually buy.
What "fabric width" actually means
When a pattern calls for "45-inch fabric," it means the pattern pieces were laid out assuming a 45-inch usable width. The bolt in the shop is measured selvage to selvage. Most fabrics lose about 1 inch total to the two selvages, so a "45-inch" bolt gives you roughly 44 inches of usable width.
Width is fixed per fabric. You can't change it — but you can choose a fabric whose width works in your favor.
The width bands you'll actually meet
| Width | What it's for | Example in our shop |
|---|---|---|
| 36″ | Vintage cottons, some specialty prints | — |
| 44–45″ | Quilting cotton, light apparel cotton | Cotton Poplin (stable, beginner-friendly) |
| 54″ | Home decor, upholstery, drapery | — |
| 58–60″ | Apparel wovens, knits, fleece | Cotton Jersey Knit |
| 108″ | Wide quilt backing | — |
Two fabrics in our shop make the point better than any table:
- 100% Cotton Swiss Dot Jacquard, 57″ wide — wider than the 44–45″ quilting standard, so it covers pattern pieces with less length.
- Cotton Denim Checkered, 33″ wide — narrower than standard, so it needs more length for the same pieces.
Same garment, two very different yardage answers.
Why width changes how much you buy (the math)
A wider bolt fits more pattern pieces side by side, so you need fewer rows of length. Industry yardage calculators bake this in: starting from a 45-inch base, fabric at 54–59 inches needs about 15% less yardage, and fabric at 60 inches or wider needs about 25% less.
Let's make it concrete with our two real fabrics, using a pattern that needs 2 yards at 45″:
- At 57″ (our Swiss Dot Jacquard): 45 ÷ 57 = 0.79 → 2 × 0.79 ≈ 1.6 yards. You save about 0.4 yards (~21%).
- At 33″ (our Checkered Denim): 45 ÷ 33 = 1.36 → 2 × 1.36 ≈ 2.75 yards. You need about 0.75 yards more (~36%).
That's the difference between a comfortable 1.6 yards and a tight 2.75 — on the exact same pattern, just because of width. Always check the width before you trust the pattern's yardage.
How to calculate yardage step by step
For any project, the layout math is:
1. Usable width = bolt width − selvages (about 1″ total).
2. Pieces across = floor(usable width ÷ piece width).
3. Rows = ceil(pieces needed ÷ pieces across).
4. Total length = rows × piece length (in inches).
5. Base yards = total length ÷ 36.
6. Add a buffer:
- Solid fabric, no matching: +10%
- Print with a repeat: +15–20%
- Napped or directional (velvet, corduroy, one-way prints): +15%
- Fabric you'll pre-wash: +5% for shrinkage (cotton typically shrinks 2–5%; polyester barely shrinks)
Round up to the nearest 1/8 yard when you buy. If the math says 1.83 yards, buy 2.
This is exactly why we list width on every fabric page — so you can do step 1 before you're at the cutting table.
Real fabrics in our shop, and their width story
| Fabric | Width note | Price | Link |
|---|---|---|---|
| Swiss Dot Jacquard | 57″ wide — saves yardage | $16.80 | product |
| Checkered Denim | 33″ wide — needs more | $19.44 | product |
| Cotton Poplin | standard apparel width, very stable | $6.94 | product |
| Cotton Jersey Knit | knit, typically 58–60″ | $12.50 | product |
| 16s Washed Denim | sturdy, pre-washed hand | $14.75 | product |
| Double-Brushed Stretch Knit | cozy both faces | $25.00 | product |
| Damask Jacquard Satin | dressy, fluid drape | $12.50 | product |
Width is only half the story — weight matters too. If you're new to reading fabric specs, our GSM guide explains why a fabric's grams-per-square-meter tells you more about hand feel than the name does, and our woven vs knit explainer covers why knits and wovens sit in different width bands to begin with.
A 3-step cheat sheet
1. Read the width first. Before you trust a pattern's yardage, check the bolt width. If yours is wider than the pattern assumed, you can buy less; if it's narrower, buy more.
2. Calculate with the formula above, then add 10–20% for matching and shrinkage.
3. When in doubt, buy the next 1/4 yard up. It's cheaper than a second trip for the same dye lot.
If you want the longer version of any of these — how yarn count affects density, or why corduroy wale changes both look and yardage — those guides are part of the Fabric 101 series. And if you're sourcing for a small brand, our texture AW26 roundup and bouclé alternative guide cover fabric choice from the buying side.