Quick Answer: Trampoline foam pit cubes are loose 6- or 8-inch foam blocks — the same product gymnastics and cheer gyms use — that create a cushioned landing zone beside or below a trampoline. Ritchie Foam’s 8x8x8-inch cubes ($299.99 for a 64-piece pack) are the best-documented option, with a published 45 ILD density and CAL 117 fire-retardant certification most competitors don’t state outright. But foam alone doesn’t make flips or somersaults safe: research on foam pit landing areas has found that cushioning reduces vertical impact force without reliably reducing cervical spine injury risk on a rotational landing, which is why we still point trick practice back to a coached gym, foam pit or not.
Foam pit cubes show up in searches for a reason that has nothing to do with marketing hype — people watching gymnastics and cheer training videos want the same soft landing zone in their backyard. That’s a real, buyable product category, not a gimmick. What’s worth sorting out before buying a few hundred dollars of foam is what it actually does and doesn’t change about safety, and which cubes are worth the money versus which listings are just foam with no certification attached.
By the numbers
- 45 ILD is the foam density Ritchie Foam and American Athletic Inc. both publish for their gymnastics-grade pit cubes — a firmness rating gyms use to spec replacement foam, and one most generic Amazon foam-cube listings don’t state at all (Ritchie Foam, American Athletic Inc.).
- CAL Technical Bulletin 117 fire-retardancy and CertiPUR-US certification (no ozone depleters, mercury, lead, or formaldehyde) are the two credentials worth checking for before buying — both Ritchie Foam and Isellfoam’s cubes carry them; not every bulk-foam listing does.
- Foam pit cushioning doesn’t equal cervical-spine safety. A peer-reviewed study on the deceleration characteristics of foam pit landing areas found that while foam reduces peak compressive landing force compared to a hard surface, that reduction doesn’t reliably lower neck-injury risk on an awkward or rotational landing — the mechanism that causes cervical spine injury on a bad flip landing isn’t the one foam depth fixes (ResearchGate).
- $1,500–$6,000+ is the typical material-cost range for a full in-ground trampoline-and-pit build (kit, excavation, retaining wall combined) — loose cubes alone for a ground-level boxed zone cost a small fraction of that (trampolines.com, fixtman.com cost guides).
- 2–4 days is roughly how long vacuum-packed foam cubes need to fully re-expand to their listed dimensions after shipping, per multiple suppliers’ own product notes — don’t judge pit depth on delivery day.
Foam pit cubes compared
| Product | Best for | Price | Cube size | Certifications |
|---|---|---|---|---|
| Ritchie Foam Gymnastic Pit Cubes | Best overall, best documented | $299.99 (64-pc, sale from $389.99) | 8x8x8 in | CAL 117, CertiPUR-US, 45 ILD |
| Isellfoam Pit Cubes (Amazon) | Best small-cube option | ~$150–300 typical (68-pc 8in; also 500-pc 6in) | 8x8x8 in or 6x6x6 in | CAL 117, CertiPUR-US |
| Foamma Pit Cubes (Amazon/Walmart) | Best for custom pit sizing | ~$100–400+ typical, size-dependent | 4, 5, 8, 9, or 10 in | CertiPUR-US |
| American Athletic Inc. Training Pit Cubes | Best commercial-grade durability | Dealer pricing only | 6 in or 8 in | CAL 117, 45 ILD, 1.45# density |
Check foam pit cubes on Amazon →
Comparing pit sizes and certifications across a dozen listings takes a while — try Amazon Music Unlimited free for 30 days and queue something up while you’re measuring the space.
Loose cubes vs. a full in-ground pit
Two different projects get searched under the same term, and it’s worth separating them before you buy anything.
Loose foam cubes are the product itself — vacuum-packed blocks that arrive flat and re-expand over a few days. Boxed in at ground level with plywood or landscaping timbers next to a trampoline ladder or common dismount spot, they add real cushioning for the cost of the foam alone, no digging required. This is what most backyard buyers actually end up with.
A true in-ground pit is a structural project: excavate a hole, build or install a retaining wall or liner to hold the sides, add a raised mesh base layer so the bottom foam doesn’t sit in ground moisture, then fill with cubes. It mirrors how many in-ground trampolines are installed, and the material costs stack up the same way — kit, excavation, and wall as three separate line items, commonly $1,500 to $6,000-plus all in. If you’re already planning an in-ground trampoline install, adding a pit alongside it is a smaller incremental cost than building one from scratch later.
Our picks
Ritchie Foam 8x8x8" Gymnastic Pit Cubes — best overall
- 45 ILD density, 1.50 lbs per cube — a published firmness spec most competing listings skip entirely.
- Meets California Technical Bulletin 117 fire-retardant standard and is CertiPUR-US certified (no ozone depleters, mercury, lead, or formaldehyde).
- Cut-to-order and made in the US (North Carolina) rather than a generic overseas bulk-foam import.
- Ships vacuum-packed — budget 4 to 7 hours for initial expansion and 2 to 4 days for full recovery before judging final pit depth.
This is the pick if you want to know exactly what you’re buying before it arrives — density, fire rating, and certification all published up front, plus US manufacturing. At $299.99 for 64 cubes it’s mid-market, not the cheapest bulk foam available, but it’s the listing with the fewest unanswered questions.
Isellfoam Pit Cubes — best small-cube option
- Available in 8x8x8-inch (68-pc) or 6x6x6-inch (500-pc) packs — the smaller cubes pack tighter into odd-shaped or narrower boxed areas.
- CertiPUR-US certified and flame-retardant; made in the USA.
- Lime green/charcoal color mix is standard across listings — cosmetic only, doesn't affect performance.
- Amazon pricing shifts with pack size and season — confirm the current listing price before ordering.
The 6-inch option is the reason this one gets a separate pick: smaller cubes fill corners and irregular pit edges more completely than 8-inch blocks, which matters more than it sounds like once you’re actually packing a boxed frame instead of a rectangular commercial pit.
Foamma Pit Cubes — best for custom pit sizing
- Widest size range on the market: 4, 5, 8, 9, or 10-inch cubes, in pack sizes from 10 up to 1,000.
- CertiPUR-US certified; ships vacuum-packed like the rest of this category, with up to 72 hours needed to fully regain shape.
- Sold loose, no cover or liner included — pair with a separate boxed frame or in-ground liner.
- The pack-size flexibility makes it the practical choice if you're filling a non-standard pit rather than a fixed commercial size.
If you’ve already dug a pit with dimensions that don’t match a standard 8-inch grid, this is the listing with enough size options to fill it without excess waste or gaps.
American Athletic Inc. (AAI) Training Pit Foam Cubes — best commercial-grade durability
- Same class of foam used in competitive gymnastics facilities — 1.45# density, 45 ILD, meets CA Technical Bulletin 117.
- Available in 6-inch or 8-inch cubes; sold through AAI's dealer network rather than direct online checkout.
- Built for repeated commercial-volume landings, which is more durability than most backyard setups need but relevant if the pit will see daily use.
- Call AAI directly for current dealer pricing — this is the one pick here without a self-checkout listing.
Most households won’t need commercial-gym durability, but if the pit is getting used every day by more than one kid, AAI’s spec sheet is the reference point for what “built to last” actually means in this category.
What a foam pit doesn’t fix
This is worth stating plainly, in the same spirit as our trampoline tricks guide: a softer landing surface changes the physics of a straight-down drop, not the physics of a bad rotational landing. The deceleration research on foam pit design specifically found that reduced peak compressive force doesn’t reliably translate into lower cervical spine injury risk when a landing goes wrong on a flip or somersault. The AAP and AAOS guidance our tricks guide cites — that flips belong in a coached gymnastics program with a trained spotter, not a home setup — doesn’t change because there’s foam underneath. A pit is a reasonable upgrade for the drops, jumps, and dismounts that are already part of normal trampoline use; it isn’t a green light for moves the same organizations advise against at home either way. See our are trampolines safe guide for the fuller injury-data picture.
The bottom line
Ritchie Foam’s 8x8x8-inch cubes ($299.99 for 64 pieces) are the best-documented buy in this category — published density, fire rating, and certification, made in the US. Isellfoam’s smaller 6-inch cubes suit odd-shaped boxed zones better than 8-inch blocks; Foamma’s five-size range is the pick for a custom-dug pit; and American Athletic Inc.’s dealer-only cubes are the commercial-grade option if the pit will see heavy daily use. Whichever you buy, remember what it changes: a foam pit softens ordinary drops and dismounts, and it does not turn flips or somersaults into a backyard-safe activity — that guidance comes from the trampoline itself, not the cubes underneath it.
Setting up a landing zone next to an existing trampoline? See our best in-ground trampoline guide if you’re planning the pit and the frame together, our trampoline tricks guide for what’s actually safe to practice at home, and our are trampolines safe guide for the full AAP/CPSC safety picture.