The Basic Yardage Formula
At its core, calculating fabric yardage comes down to one question: how much area do I need to cover, and how wide is my fabric?
The formula is:
Yards Needed = (Total Area Needed ÷ Fabric Width) ÷ 36
That 36 is there because one yard equals 36 inches. So you're converting from inches to yards.
Let's say you need to cover 5,000 square inches of area, and your fabric is 60 inches wide. That's 5,000 ÷ 60 = 83.3 inches of fabric length. Divide by 36 and you get 2.3 yards.
But here's the thing. You almost never need exactly that amount. There's shrinkage, seam allowances, pattern matching, and cutting errors to think about. I'll cover all of that below.
Always Pre-Wash Before You Calculate
I cannot stress this enough. If you skip pre-washing, you will regret it the first time you launder your finished project and it shrinks.
Here's what I do. Cut a 12-inch square from your fabric. Measure it precisely. Wash it exactly the way you plan to wash the finished item. Same temperature, same cycle, same drying method. Then measure it again.
If your 12-inch square is now 11.4 inches, that's a 5% shrinkage rate. You need to add that 5% to every measurement in your project.
For a project that needs 3 yards of fabric, 5% shrinkage means you should buy 3.15 yards. Round up to 3.25 or 3.5 yards because fabric is usually sold in quarter-yard increments.
Natural fibers shrink more than synthetics. Cotton and linen can shrink 3 to 8%. Wool can felt and shrink dramatically if you're not careful. Polyester barely shrinks at all. Blends fall somewhere in between.
Handling Pattern Repeat
If your fabric has a directional pattern or a repeating design, you need extra yardage to make sure the pattern lines up across seams.
The pattern repeat is the distance before the design starts over again. You can measure it by looking at the fabric and finding where one motif ends and the identical motif begins.
For each piece you're cutting, you need to add one full pattern repeat to the cut length. So if your pattern repeat is 12 inches and your piece needs to be 36 inches long, you actually need to cut 48 inches to ensure the pattern matches.
This adds up fast. For curtains with a large pattern repeat, you might need 20 to 30% extra fabric. For small, non-directional prints, you might not need any extra.
Here's a rule of thumb. If the repeat is under 6 inches, add 10% extra. If it's 6 to 12 inches, add 20%. If it's over 12 inches, add 30% or more.
Fabric Widths: They're Not All the Same
This is something beginners often overlook. Fabric comes in different widths, and the width dramatically affects how much you need to buy.
Common widths you'll encounter:
45 inches: Standard for quilting cotton, fashion fabric, and many apparel textiles. 54 inches: Common for home decor, drapery, and some apparel. 60 inches: Common for upholstery, fleece, and wide drapery. 108 to 120 inches: Extra-wide backing for quilts and large drapery panels.
The wider the fabric, the less length you need. If a project calls for 4 yards of 45-inch fabric, you might only need 3 yards of 60-inch fabric.
Always check the bolt width before you start calculating. It's printed on the bolt label, and most online fabric stores list it in the product description.
Upholstery Yardage: A Rough Starting Point
Upholstery is tricky because every piece of furniture is different. But here are some ballpark numbers to get you started.
Dining chair seat only: 1/2 to 3/4 yard Dining chair with back: 1 to 1.5 yards Armchair: 6 to 8 yards Loveseat: 10 to 12 yards Standard sofa: 12 to 16 yards Sectional sofa: 18 to 24 yards
These assume 54-inch wide upholstery fabric with no pattern repeat. Add 2 to 3 yards if you have a large repeat or a directional pattern.
The best approach is to measure each section of your furniture. Add 4 to 6 inches per piece for wrapping, tucking, and seams. Then calculate the total area and divide by your fabric width.
If you're recovering something with lots of curves, tufting, or skirt details, add an extra 10 to 15% on top of everything else.
Quilting Fabric: Backing and Binding
For quilts, you need fabric for the top, the backing, and the binding.
Backing: Add 8 inches to both the width and length of your quilt top. So a 60 × 80 inch quilt needs backing that's 68 × 88 inches. If your fabric is 45 inches wide, you'll need to piece the backing from multiple widths. Calculate: 88 ÷ 45 = 1.96, so you need 2 widths. Each width needs to be 68 inches long, so you need 136 inches total, which is 3.78 yards. Round up to 4 yards.
Binding: Calculate the perimeter of your quilt and add 12 inches for corners and joining. For a 60 × 80 quilt: 2 × (60 + 80) + 12 = 292 inches. Binding is typically cut at 2.5 inches wide. You need 292 ÷ 40 (usable width after trimming) = 7.3 strips. At 2.5 inches per strip, that's 18.25 inches of fabric, or about half a yard.
Batting is sold pre-cut by size, so you just need to match it to your quilt dimensions.