7 Costly Mistakes to Avoid When Choosing Sizes for Decorative Pillows

Have you ever made beautiful decorative pillows, placed them on the sofa, chair, or bed—and thought:

Something just doesn’t look right.

The fabric is beautiful. The workmanship may be excellent. The colors work perfectly in the room.

But the pillows still feel too small, too large, too crowded, or simply out of proportion.

If you’ve struggled with choosing the right decorative pillow size, you’re not alone.

After nearly four decades of designing and fabricating custom pillows, bedding, and soft furnishings, I’ve learned that professional-looking pillows begin long before the fabric is cut.

They begin with understanding size, scale, proportion, and the space where the pillow will live.

Here are seven common mistakes—and what to consider instead.

1. Choosing the Pillow Before Considering the Space

It’s tempting to start with familiar pillow sizes: 18″, 20″, 22″, 24″.

Instead, start with the furniture.

Look at the overall size of the sofa, chair, window seat, bench, or bed. Consider the available width, depth, and height.

Decorative pillows perfectly proportioned on a large sofa may overwhelm a small chair.

Let the space help determine the pillow—not habit.

Donna’s Perspective

You can’t measure the right pillow until you’ve decided what the right pillow is. Start with the space and consider how you’ll use the pillow.

2. Assuming One Pillow Size Works Everywhere

There isn’t one “correct” size for decorative pillows.

Scale and proportion matter.

Larger pillows can create a luxurious, inviting feeling on generously sized furniture. Smaller pillows can add color, pattern, texture, and interest—but may feel lost if they’re undersized for the space.

On a bed, mattress width also matters. Pillow groupings should relate visually to the bed’s size rather than using the same arrangement everywhere.

Good proportion creates balance.

3. Using Too Many Pillows

Yes, there really can be too much of a good thing!

Decorative pillows should make furniture look inviting—not make people wonder where they’re supposed to sit.

Before adding another pillow, consider how the furniture will actually be used.

Is there comfortable room to sit?

Does the arrangement feel welcoming?

Could you remove one pillow without losing the overall design?

Beauty and function should work together.

Donna’s Perspective

Before adding one more pillow, ask yourself: Where will someone sit? The best pillow arrangements enhance the furniture without getting in the way of how it’s meant to be enjoyed.

4. Guessing at the Size Instead of Trying It First

Not sure whether you need a 20″, 22″, or 24″ pillow?

Don’t guess.

One of the most useful things you can do is keep a selection of pillow inserts in common sizes on hand.

Place them on the actual sofa, chair, window seat, bench, or bed. Step back and look at the proportions.

If you’re designing for a homeowner, let them see the options too.

You may both be talking about a “large pillow” while picturing two very different things.

Showing rather than simply describing creates better communication.

5. Assuming Everyone Measures Decorative Pillows the Same Way

Here’s where things can become confusing—and sometimes expensive.

No universally accepted industry standard requires every designer, workroom, manufacturer, or supplier to measure decorative pillows the same way.

A pillow may be measured seam-to-seam or corner-to-corner, and construction details can affect those finished measurements.

So don’t communicate only the size.

Ask:

“How was the pillow measured?”

A few extra words before the project begins can prevent an expensive remake later.

Donna’s Perspective

The measurement itself isn’t usually the problem—miscommunication is. Make sure everyone is talking about the same measurement before you cut the fabric.

6. Making the Pillow Cover Before Measuring the Insert

The pillow cover is only part of the equation.

The insert affects the finished size, fullness, shape, and overall appearance of your pillow.

And inserts labeled the same size aren’t necessarily identical.

That’s why one of my workroom rules is simple:

Never make a pillow cover until you have the insert in hand.

Measure the actual insert before cutting your fabric.

That small step can make a big difference in creating a full, professionally finished pillow.

Read more about inserts for decorative pillows here: Pillow Forms – Everything You Ever Wanted to Know

7. Focusing on Size but Forgetting Function

A pillow can be beautifully proportioned and still be wrong for the space if it doesn’t function well.

Think about why the pillow is there.

A bolster on a banquette may provide back support.

A pillow on a chair shouldn’t push the person sitting there uncomfortably forward.

Decorative pillows on a bed can create beautiful layers, but the grouping should still feel proportional, not overwhelming.

A window seat needs enough open space to remain usable.

Don’t choose a pillow based on measurements alone.

Consider the person, the furniture, and the purpose.

Donna’s Perspective

Beautiful design isn’t just about how something looks. When proportion, comfort, and function work together, the entire space feels better.

Now You Know What to Avoid. Here’s How to Get It Right.

You don’t need to memorize a long list of “correct” pillow sizes.

Instead, learn to measure the space, understand proportion, consider function, and communicate measurements clearly.

And sometimes, seeing the difference is much easier than reading about it.

That’s why I created my FREE guide:

Beautiful Pillows Start with the Right Measurements

Inside, you’ll find practical tips and original illustrations showing how to measure, size, proportion, and place decorative pillows on:

Sofas • Chairs • Beds • Benches • Window Seats • Banquettes

You’ll also learn more about professional measuring practices, pillow inserts, and the little details that can make a big difference in your finished results.

Fill out the form above to download your FREE copy of Beautiful Pillows Start with the Right Measurements 

My goal isn’t to give you more rules to memorize. It’s to help you understand the why behind beautiful pillow design so you can make those decisions with greater confidence.

Sew with Joy • Create with Confidence • Live Inspired

— Donna Cash

Do you struggle to insert zipper slides onto a zipper chain? In this video, Inserting a Zipper Pull on an Invisible Zipper, you’ll see a close-up view of how I tackle this part of decorative pillow making. It’s quick and easy. Be well and never stop creating!