Shredded memory foam is the fill people reach for when they want a bean bag, pillow, dog bed, or cushion to feel plush and stay that way. The only tricky part is figuring out how much to buy. Too little and the project is flat; too much and you are storing a bag of foam in the garage. This guide gives you a quick reference, a simple formula, and real examples so you can order once and be done.
Quick reference: bag size to cubic feet
Our Shredded Memory Foam Fill comes in four sizes. Here is roughly how much space each one fills once it has expanded.
| Bag size | Fills approximately | Typical project |
|---|---|---|
| 5 lb | About 2 cubic feet | One small pillow or cushion, topping up a pillow |
| 10 lb | About 4 cubic feet | 2 to 3 standard pillows, a small dog bed |
| 20 lb | About 8 cubic feet | Small bean bag, several cushions, a medium dog bed |
| 40 lb | About 16 cubic feet | Large bean bag, large dog bed, a sofa’s worth of cushions |
These numbers assume a medium fill. Add 10 to 20 percent more foam if you want a firmer, fuller feel, and use a little less for a softer, squishier result.
The formula: find your cubic feet
Every project comes down to one number: the volume of the thing you are filling, in cubic feet. Here is how to get it.
- Measure the length, width, and height of the cover or shell in inches.
- Convert each to feet by dividing by 12.
- Multiply length x width x height. That is your cubic feet.
- Divide by 0.4 to get the pounds of shredded foam you need at a medium fill (since 1 lb fills about 0.4 cubic feet).
For round or irregular shapes like a bean bag chair, measure it as a box (the widest width, the longest length, the tallest height), multiply, and then take about 70 percent of the result, since a round shape holds less than the box it fits in.
Worked examples
A standard bed pillow
A queen pillow cover measures about 20 by 30 inches and you want it around 6 inches thick when full. That is 1.67 x 2.5 x 0.5 = about 2.1 cubic feet. At medium fill you need roughly 5 lb per pillow, so a 10 lb bag fills two pillows with a little left over for topping up. Side sleepers who like a tall, firm pillow should plan on the higher end.
A dog bed
A large dog bed cover, 36 by 48 inches and 8 inches tall, is 3 x 4 x 0.67 = about 8 cubic feet. That is a 20 lb bag for a medium fill, or closer to 25 lb if your dog is heavy and you want it to stay lofted. Shredded memory foam is a great dog bed fill because it does not pack down into a pancake the way polyester does, and it is hypoallergenic and low odor.
A bean bag chair
A bean bag that measures roughly 36 inches across and 30 inches tall is about 3 x 3 x 2.5 = 22.5 cubic feet as a box; take 70 percent for the round shape and you get about 16 cubic feet, which is one 40 lb bag. A larger 48 inch lounger-style bean bag can take 60 lb or more; order a 40 and a 20. Under-filled bean bags are the most common complaint we hear, so err on the side of more.
Sofa or patio cushions
A back cushion 24 by 24 by 6 inches is 2 x 2 x 0.5 = 2 cubic feet, so about 5 lb each. Four cushions is a 20 lb bag. For seat cushions that get sat on all day, add 20 percent so they do not flatten.
Topping up an adjustable pillow
If you already own a shredded foam pillow and it has settled, a 5 lb bag refreshes several pillows. Our Adjustable Pillow and Body Pillow both ship with extra fill, but a bag on hand means you can top up whenever you like.
Firm, medium, or soft?
Fill level changes the feel more than anything else. Start with the medium number from the formula, fill the cover, and sit or lie on it. If you bottom out, add more. If it feels stiff, take some out. Shredded foam shifts to match the shape pressing into it, so it never feels like a solid block, but more foam in the same cover does push back harder.
Tips for a good result
- Let it expand first. Our fill ships vacuum-compressed. Open the bag and give it a few minutes to a couple of hours to fluff up before you stuff anything; it will look like much more foam than you expected.
- Work in a clean, contained space. Shredded foam is easy to handle but it does get around. Fill inside a large box or a bathtub.
- Use a zippered inner liner for bean bags and dog beds so you can wash the outer cover without emptying the foam.
- Fluff regularly. Shaking or kneading the cushion opens the gaps between clusters and restores loft.
- Keep the extra. Leftover foam is useful for topping up later. It stores fine in a sealed bag.
Why our fill is different
A lot of shredded foam on the market is scrap: mixed densities, mystery colors, sometimes bits of bonded carpet pad. Ours is 100 percent gel-infused memory foam shredded from the same blocks we pour for our toppers in Phoenix, AZ. It is CertiPUR-US certified, hypoallergenic, low odor, and consistent from bag to bag, with no fillers or mixed materials. It also holds loft longer than polyester fill.
Ready to fill something?
Do the math, round up, and pick your bag. Our shredded memory foam fill ships same or next business day, free to the lower 48, and it is covered by our 30-Night Happiness Guarantee like everything else we make. If you are not sure how much to order, send us your project dimensions through our contact page and we will work it out with you.