Container sizes
How big is a 20 yard dumpster, really?
Roll-offs are sold by cubic yards of space inside the box. Here is what those numbers mean on your driveway.
One cubic yard, in plain terms
A cubic yard is a cube 3 feet on each side, which is 3 x 3 x 3 = 27 cubic feet. So a 20 yard box holds about 540 cubic feet and a 40 yard box about 1,080.
For a San Antonio yardstick: the city's curbside bulky pile limit is 8 cubic yards, or 216 cubic feet. That is a bit less than half of a 20 yard container.
Outside measurements
Manufacturers differ by a few inches, and the smallest boxes vary the most. These ranges come from two published spec lists.
| Size | Length | Width | Wall height |
|---|---|---|---|
| 10 yard | 10.5 to 12 ft | 8 ft | 3.5 to 4.5 ft |
| 20 yard | 22 ft | 8 ft | 4 to 5 ft |
| 30 yard | 22 ft | 8 ft | 6 ft |
| 40 yard | 22 ft | 8 ft | 8 ft |
Notice that 20, 30 and 40 yard boxes share the same footprint. The extra space comes from taller walls. If you are tight on driveway room, a bigger box does not need more ground, only more lifting over the side.
Matching the size to the job
Smaller boxes (10 to 15 yd)
- Dense loads: tile, dirt, broken concrete
- One bathroom gut
- A garage with no large furniture
Mid size (20 yd)
- A kitchen tear-out with cabinets
- Whole-house cleanouts after a move
- Fence replacement
Large (30 to 40 yd)
- Additions and new builds
- Bulky, light debris that takes space but not weight
- Commercial cleanouts
Not sure?
- Pick "Help me pick" on the form
- Tell the haulers what is going in
- They size it from experience
Weight usually runs out before space
Each rental includes a set weight, and anything over is billed per ton. Roofing, concrete and wet soil hit that limit with lots of empty space left. Ask every hauler the same thing: how many tons are included and what each extra ton costs. Comparing only the headline price misses this.
Checked against
- Redbox+, dumpster dimensions read November 4, 2026
- Custom Truck One Source, roll-off sizes read November 4, 2026
- City of San Antonio SWMD, Curbside brush and bulky rules (8 cubic yard pile limit) read November 4, 2026