How to Use the Quilty Sidekick Binding & Backing Tool

(With Cost Comparison: 108" Wide Fabric vs 42" WOF Strips)

You’ve finished the top, the quilt’s looking great — now it’s time to sort out the backing and binding. This is the stage where a lot of us get stuck. How much fabric do I actually need? Do I have enough? Should I go with wideback or piece something together? That’s where this calculator comes in — to make all of that just a bit easier.

That’s exactly why I created this tool.

The Quilty Sidekick Binding & Backing Calculator takes the guesswork out of fabric requirements. Just plug in your quilt size and preferences, and it’ll give you the yardage for both the backing and binding.

In this post, I’ll walk you through how to use the tool step-by-step, and we’ll also compare two common options for backing fabric:

• 108” wide fabric

• 42” width-of-fabric (WOF) strips that are pieced together

We’ll look at cost, ease of use, and what works best depending on your project.

Where to Find the Tool

You can use the calculator directly on my website: https://quiltysidekick.com/bindingtool

It’s free to use, and you can run as many different calculations as you need. Perfect for those moments when you're standing in the fabric store wondering if you've got enough. how many strips do I need for my binding.

Lets have a look.

Step-by-Step: How to Use the Binding & Backing Tool

1. Enter Your Quilt Dimensions

Start by typing in the width and length of your quilt in inches. Use the finished size before quilting.

If you're sending your top to a long arm quilter (like me) NZ only lol, don’t forget to add extra fabric on all sides for loading. Most long armers ask for around 4" of overage on each side, so the tool adds 8" total to both your width and length you don't need to add it.

2. Check Binding Requirements

Scroll down to the binding section of the calculator.

The default strip width is set to 2.25", which is what I use for most of my quilts. I typically use cotton batting, which is a little thinner than polyester, and I find that 2.25" binding gives a clean finish without feeling bulky.

The calculator is designed for straight grain binding. That’s the method I use — I don’t tend to make bias binding, so it’s not included here.

The calculator will show:

• Total binding length required

• Number of strips to cut

• Yardage needed for binding

3. Choose Your Fabric Width

Select the fabric width you’re planning to use for the backing:

Choose 42" for standard quilting cotton if you have stash available

or

Choose 108" if you’re using wide back fabric

The tool will calculate:

• Total yardage needed

• How many WOF strips (if you’re piecing backing)

• Whether seams are required

4. Optional Adjustments

If you’re working with metric fabric, directional prints, or want to add extra buffer, you can make manual adjustments based on the base calculation. The tool gives you a solid starting point to work from.

Just press Calculate and you have all the answers.

Cost Comparison: 108” Wide Fabric vs 42” WOF Backing

Let’s walk through a real example using the calculator.

Say your finished quilt top measures 80" x 80". With longarm overage, that means you'll be calculating for 88" x 88".

Option 1: 108” Wideback

• Fabric width: 108"

• Quilt size (with overage): 88” x 88”

• Calculator result: 2.5 yards

• Average fabric price: $1.22 per inch

• Total cost: Approximately $107.60 NZD

Option 2: 42” WOF Pieced Backing

• Fabric width: 42"

• Quilt size (with overage): 88” x 88”

• Calculator result: 5.23 yards

• You’ll need: 3 WOF panels sewn together

• Average fabric price: $28 per yard

• Total cost: Approximately $188.16 NZD

So… Which One Should You Choose?

There’s no one-size-fits-all answer — it depends on your project and what’s most important to you.

If you’re short on time or want something simple to load on the longarm, a wideback is often the easiest option.

But if you’ve got fabric in your stash you’d like to use, or you enjoy the process of piecing a backing, then working with 42" WOF strips makes perfect sense.

Either way, the calculator helps you plan with confidence — so you can stop guessing and know exactly how much fabric to buy.

Final Thoughts

Backing and binding don’t have to be the stressful part of quilting. With the right numbers in front of you, it becomes just another creative step — one you can plan with confidence.

You can try the calculator here:

https://quiltysidekick.com/bindingtool

Want to Add a Tool Like This to Your Own Website?

If you're a longarm quilter or pattern designer and you'd like to offer a calculator like this to your own clients, I’ve put together a free mini course that shows you exactly how to do it.

No coding required — just simple, step-by-step instructions to help you embed it on your own site.

You can access it through the Free Quilter’s Hub:
https://hub.quiltysidekick.com/login

Inside the hub, you’ll also find a few digital pantos, patterns, and tutorials — and I’m adding new resources all the time. If you're looking for a few freebies or want to try something new, you'll find them there.

Share with a Quilty Friend

If you found this helpful, pass it along to your guild, share it in a quilting group, or bookmark it for the next time you’re planning your fabric needs. It just might save someone a fabric crisis.