TL;DR: Measuring a glider or porch swing for custom cushions takes about 10 minutes and four key numbers: seat width, seat depth, back width, and back height. Always measure the chair frame — not your old cushion. If your back is curved or the shape feels tricky, send us a photo and we'll draw a diagram showing exactly where to measure. This guide walks you through every step.
You finally found it. Maybe it's a vintage iron glider that belonged to your grandparents. Maybe it's a porch swing you've been meaning to outfit for two summers running. Either way, you know you need cushions — and you're now staring at a tape measure wondering where to even start.
You're not alone. "I can't figure out how to determine the sizes" is one of the most common things we hear from customers ordering custom swing and glider cushions. And honestly? It makes sense. A glider has a curved back, a floating seat, and frame dimensions that vary wildly between manufacturers. A porch swing is long and awkward to measure alone.
The good news: you only need four numbers, the right tool, and about ten minutes. This guide breaks down exactly what to measure for both gliders and porch swings, including the curved-back trick most people miss. And if you get to the end and still feel uncertain, there's an even easier option.
What You'll Need Before You Start
Gather these before you kneel down next to your chair:
- A rigid measuring tape (the kind that stays straight, not a soft fabric sewing tape)
- A pen and paper, or your phone's notes app
- A helper, if possible (especially for long porch swings)
That's it. You don't need templates, you don't need string, and you definitely don't need to ship your old cushions anywhere. More on that last part in a moment.
One important rule before any measuring happens: measure the chair frame, not your old cushion. This is the most common mistake people make, and it's worth repeating. Over time, foam compresses and fabric stretches. A cushion that started at 20 inches deep might measure 17 or 18 inches after a few seasons. As the experts at Cushion Source note, ordering based on your old cushion's current dimensions will result in new cushions that don't actually fit the furniture. Always go back to the frame.
How to Measure a Glider Seat Cushion
A glider seat cushion needs three numbers: width, depth, and thickness.
Width: Place your tape measure across the inside of the seat, from the inside face of one armrest to the inside face of the other. This is the measurement your cushion needs to fill. Don't measure the outside of the arms or the total frame width. You want the space where a person actually sits.
Depth: Measure from the very front edge of the seat frame to the point where the seat meets the back of the chair. For a glider, this is usually where the back cushion will rest or where the frame connects. Don't pull the tape to the back of the frame; stop where the seat ends.
Thickness: This is how tall your cushion will be, not how long. Common choices are 3 inches (a slim profile that works well for lighter seating), 4 inches (the most popular option for everyday outdoor use), and 6 inches (for a deep, lounge-style feel). If you're replacing a cushion you loved, measure its current height before it compressed too much — that gives you a decent starting point.
Write all three numbers down. For example: 21" wide x 20" deep x 4" thick.
How to Measure a Glider Back Cushion (Including Curved Backs)
What if my glider back is curved? Here's how to measure it.
For a curved glider back, measure the width at the widest point (usually near the bottom) and measure the height from the top of the seat cushion to the highest point of the back frame. Give us the highest number. We'll shape the cushion to match the curve.
This is one of those things that trips people up because it feels like it should be more complicated. It's not.
Here's how to do it step by step:
Back width: Measure across the back frame at its widest point, from the inside of one side rail to the other. On most gliders, that's near the bottom of the back where it connects to the seat.
Back height: Measure from the top of the seat (where the seat cushion will sit) up to the top of the back frame. If the back curves and you're not sure where the "top" is, measure to the highest point of the curve.
One critical adjustment: Subtract your seat cushion thickness from the back height measurement. This is important. If your back is 22 inches tall but your seat cushion is 4 inches thick, your back cushion should be about 18 inches tall — otherwise it'll poke up above the top of the chair frame, which looks off and can shift out of place.
For example, one of our customers in Pennsylvania had a vintage glider with a back that arched to 31 inches at its highest point. No standard cushion on the market came close. Once she took that single measurement and subtracted her seat cushion thickness, we had exactly what we needed to make her a custom set.
How to Measure a Porch Swing Seat Cushion
How do I measure a porch swing cushion if it's really long?
For a porch swing, measure the full length of the seat from one inside end to the other, the depth from front to back, and your preferred thickness. Most swings fall between 48 and 72 inches long. If you have a helper, hold one end of the tape while they hold the other — measuring alone on a 60-inch swing is genuinely difficult.
Porch swings have a slightly different challenge than gliders: they're often wider than they look, and the depth can be surprisingly generous on older or handmade styles.
Length (width of the swing seat): Measure from one inside arm (or end bracket) to the other in a straight line. This is the number that matters most for fit. Standard porch swings tend to fall into 4-foot (48"), 5-foot (60"), or 6-foot (72") ranges, but plenty of custom-built or vintage swings fall outside those tidy numbers.
Depth: Measure from the front edge of the seat boards back to where the swing meets the back supports. On a deep-seat swing, this can be 24 to 30 inches. On a simpler slatted swing, it might be 18 to 20 inches. Don't guess — that extra 4 inches of depth changes the whole comfort level.
Thickness: Same logic as the glider seat: 3 inches is minimal, 4 inches is comfortable for most people, and 6 inches is for the "I want this to feel like a sofa" effect.
If your swing also has a back section, measure that the same way as the glider back above: width across and height from the top of the seat to the top of the back frame, minus the seat cushion thickness.
The Tool You Probably Haven't Tried: The Photo Method
Here's something we've learned from years of helping customers with unusual furniture: sometimes the fastest measuring guide is a photo.
If your glider or swing has a curved back, an odd armrest shape, a non-rectangular seat, or you genuinely can't figure out where one part ends and another begins — send us a couple of photos. A shot from above and one from the side. That's usually all we need.
We'll look at the photos and draw a simple diagram marking the exact spots to measure. You measure those spots, send us the numbers, and we're off. No guessing, no back-and-forth about whether you measured the right place.
We did exactly this for a customer in Ohio who had a wrap-around dinette in his RV. The shape was so unusual that describing it in words felt impossible. He sent photos, we sketched out the measurement points, and a few days later he had the dimensions we needed to make his cushions.
It's not a last resort — it's honestly one of the best ways to get a perfect fit the first time. You can reach us through the contact page anytime.
Three Mistakes That Lead to Cushions That Don't Fit
Don't let these small errors derail an otherwise easy process.
Measuring the old cushion instead of the frame. We've said it once but it's worth saying again: foam compresses over time. A cushion that was once 21 inches deep might measure 18 or 19 now. Measure the chair.
Forgetting to subtract seat cushion thickness from back height. If your back frame is 24 inches tall and your seat cushion is 4 inches thick, a 24-inch back cushion will sit 4 inches above the top of your chair. Order an 20-inch back cushion instead. This is the step most people miss.
Measuring the outside of the arms instead of the inside. The usable seat width is between the arms, not across the arms. For some gliders, this difference can be 3 to 6 inches — enough to make a cushion feel uncomfortably tight or sloppy.
Take these into account and you'll be set.
What to Do With Your Measurements Once You Have Them
Once you've got your four numbers — seat width, seat depth, seat thickness, back width, back height — you're ready to order.
Head to the porch swing cushions collection or the outdoor seat cushions page and enter your exact dimensions. You'll also choose your fabric (about 23 outdoor colors, all waterproof and UV-resistant) and any extras like back ties or Velcro.
Not sure which fabric will look right with your furniture? We recommend checking out the fabric gallery and free swatch page — you can order physical samples before committing, which is especially helpful for outdoor colors that look different on a screen than in real sunlight.
If you're getting a glider with both a seat and a back cushion, you'll order them as two separate items. They won't be sewn together unless you ask. That makes each one easy to clean, flip, or replace independently — a detail that makes a lot of sense once you've lived with it for a season.
And if after all this you still have questions about whether your furniture qualifies as a "standard" shape or something that needs extra attention, take a look at our complete custom swing and glider cushion guide for a fuller overview, or just reach out directly.
Closing Thought
Measuring your glider or porch swing doesn't have to be the part that holds up the whole project. Four numbers. A rigid tape. Ten minutes. That's the whole job.
And if you get stuck, send us a photo. We genuinely enjoy the puzzle of an unusual chair — and after helping customers from Utah to Pennsylvania to Ohio figure out their measurements, there aren't many shapes that surprise us anymore.
Your cushions should fit the chair you actually have, not some average version of it. That's the whole reason custom exists.
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Frequently Asked Questions
Should I measure my old cushion or the chair frame? Always measure the chair frame. Foam compresses and fabric stretches over years of use, so old cushions often run smaller than their original dimensions. Measuring the furniture itself guarantees your new cushion fits the actual space, not the shrunken ghost of the last one.
What if my glider back is curved? How do I measure it? Measure the width at the widest point of the back frame, and the height from the top of the seat cushion up to the highest point of the curve. Give us the full height to the peak of the arch. We'll build the cushion to fit the curve from there. The main thing is: don't skip that measurement just because it's not a straight line.
Do I subtract my seat cushion thickness from the back cushion height? Yes, and this step matters. If your chair back is 24 inches tall but your seat cushion is 4 inches thick, your back cushion should be 20 inches tall — otherwise it'll stick up above the top of the frame. It's a simple subtraction, but it's easy to forget until you're holding a cushion that's awkwardly tall.
What measurements does uscushion.com need to make my cushion? For a seat cushion: width, depth, and thickness. For a back cushion: width, height (minus seat thickness), and thickness. If you're ordering a matching set, provide the measurements for each piece separately. You can also send us photos and we'll help you identify exactly where to measure.
What if I can't figure out where to measure on my glider? Send us a photo. Seriously. A quick shot from above and from the side gives us enough to draw a measurement diagram specific to your chair. We'll mark the exact points to measure and send it back to you. This is a free part of our ordering process and works especially well for antique gliders, non-standard shapes, and RV or boat seating. Reach out through our contact page anytime.
