The cheapest DIY compost bin is a plastic trash can with holes drilled in it — free if you already own one, done in under an hour. The sturdiest is a three-bay concrete block system that costs around $110 and takes a weekend. In between sit pallet bins, wire-mesh cylinders, and single-block bays, each trading cost against durability and capacity. Below are five tested designs from university extension services, with materials lists, dimensions, and what each one actually costs to build, so you can match the bin to your yard and your Saturday.
Compare the five builds at a glance
| Build | Cost | Build time | Capacity | Best for |
|---|---|---|---|---|
| Trash can bin | $0–30 | Under 1 hour | 30–55 gallons | Renters, small yards, first-timers |
| Wire-mesh cylinder | $40–75 | 1–2 hours | 8–10 bags of yard waste | Fast, movable, minimal tools |
| Pallet bin (3-sided) | $0–20 | 2–3 hours | ~27 cubic feet (3×3×3 ft) | Free materials, larger volumes |
| Single concrete block bay | Under $60 | Half a day | 10–12 bags | Permanent, rodent-resistant setup |
| Three-bay concrete block system | Under $110 | Full weekend | 30–38 bags, turnable | Serious composters, active turning |
Build 1: The trash can bin (cheapest, fastest)
A 30- to 55-gallon plastic or metal trash can with a locking lid becomes a closed compost bin with nothing but a drill. Drill four or five holes in the bottom — one centered, the rest spaced roughly 6 inches (15 cm) apart in a ring — for drainage. On the sides, drill a row of holes about 6 inches (15 cm) down from the rim, spaced 4–6 inches (10–15 cm) apart, then repeat rows every 6 inches down the can. Use a 1/2-inch (12 mm) bit; if the can is plastic, brace a scrap 2×4 inside while drilling so it doesn’t crack or warp.
Set the finished can on a few bricks or blocks to lift it off the ground and let air and excess moisture escape from the bottom. Total cost is close to zero if you’re repurposing an old can, or under $30 for a new one. Trade-off: a sealed can holds heat and moisture well but needs manual turning — roll it on its side and shake, or drill a rod through the center for a spin-turn design, since there’s no easy way to fork-turn contents through a lid.
Build 2: The wire-mesh cylinder (fastest to set up outdoors)
This is the design most university extensions recommend as the entry point for anyone with outdoor space. Bend a 12½-foot (3.8 m) length of 36-inch (0.9 m) wide, 1/2-inch hardware cloth into a circle and fasten the overlapping ends with wire ties or hog rings — no posts, no digging. The resulting cylinder is roughly 4 feet (1.2 m) across and holds the equivalent of 8–10 bags of yard material, according to University of Wisconsin–Madison Extension. Budget $40–75 depending on hardware cloth gauge; heavier 1×1-inch galvanized mesh costs more but resists sagging and rodents better than thin chicken wire.
To empty or turn it, lift the entire cylinder up and off the pile, set it down next to the now free-standing heap, and fork the material back in — this aerates the whole pile in one motion, which is the main advantage over a fixed bin.
What materials do you need for a pallet compost bin?
Three shipping pallets, six galvanized corner brackets, screws, and (optionally) a roll of chicken wire stapled to the inside to stop material falling through the slats. Standard pallets run about 48 x 40 inches (1.2 x 1 m), so three standing on edge and screwed together at the corners make a roughly 3 x 3 x 3-foot (0.9 m) open-topped bin — the minimum volume extension services recommend for a pile that heats up well. A fourth pallet, hinged rather than screwed, makes a swinging front door for easier access.
Source pallets stamped “HT” (heat-treated) rather than “MB” (methyl bromide-fumigated) — the Arkansas Extension notes fumigated pallets aren’t appropriate near anything destined for a food garden. If pallets are free (check behind hardware stores and garden centers, with permission), total cost is under $20 for hardware. Full build guidance, including troubleshooting a pile that won’t heat up, is in our how to start composting guide.
Build 4: The single concrete block bay
Stack standard concrete blocks three sides high, leaving 1/2-inch (12 mm) gaps between blocks in each course for airflow, and stagger the joints between layers the way you’d lay bricks, for stability. A one-bin unit needs about 38 blocks and, for extra rigidity, metal fence posts driven through the block cavities at the corners. University of Wisconsin Extension prices a one-bay block unit at under $60, holding roughly 10–12 bags of yard waste. Leave the front open, or stack blocks only to half height there, so you can fork material in and out without climbing over a wall.
Concrete block bins are the most rodent- and weather-resistant of the five designs here and need essentially no maintenance once built — the trade-off is that they’re not portable and the driest to move if you change your mind about the site.
Build 5: The three-bay concrete block system
The same block-and-post method, extended to three side-by-side bays, is the design serious composters end up building because it turns a hobby into a working process. One bay takes fresh material, the second holds actively decomposing compost, and the third holds material that’s nearly finished — you shift material one bay over every few weeks instead of turning it in place. University of Wisconsin Extension specs this at 86 blocks, 4 half blocks, and 11 metal posts, for a total under $110, with a combined capacity of 30–38 bags. It’s the only build here designed around active turning rather than passive decomposition, which is also why it’s the fastest of the five to produce finished compost on a repeatable schedule.
How much space does a DIY compost bin actually need?
Plan for the bin footprint plus turning room. A single 3 x 3-foot (0.9 m) bin needs roughly 3 x 6 feet (0.9 x 1.8 m) of total clearance so you can fork material in and out without straddling the pile. Three-bay systems need proportionally more — closer to 10 x 4 feet (3 x 1.2 m) — since you’re moving material sideways between bays rather than just turning in place.
Do DIY compost bins need a solid bottom?
No, and most extension designs specifically avoid one. Composting depends on contact with soil organisms and drainage of excess moisture; a bin set directly on bare ground (not concrete or pavement) lets worms and microbes migrate in and lets liquid drain rather than pool. If you’re composting on a hard surface, add a shovelful of garden soil to the base to inoculate the pile before you start layering material.
Which DIY compost bin design is right for you?
Match the bin to constraints, not to what looks impressive. A trash can or wire-mesh cylinder is the right call if you’re renting, might move within a year, or just want to find out whether composting fits your routine. Pallet bins suit anyone with a full-size yard and access to free pallets who wants volume without spending much. Concrete block systems are for a permanent spot you’ve already decided on — they’re the most work upfront and the least flexible afterward, but the lowest-maintenance option for years of use. For the day-to-day mechanics once a bin is built — what to add, how wet to keep it, and how to fix a smelly pile — see our guide to starting composting.