170 Gallon Deck Box Dimensions and Sizing: What Fits Inside?

A 170-gallon deck box is a storage class, not a fixed size — Suncast’s BMDB1171 measures 58 x 29.25 x 29.25 inches outside and 56 x 26.5 x 27 inches inside, while Keter’s 170-gallon box is 57 x 27.8 x 29 inches outside.

Two boxes with the same gallon rating can differ by nearly an inch in width and more than an inch in depth. That gap decides whether a folded chaise cushion slides in flat or wedges at an angle. Sizing comes down to three numbers — interior width, depth, and height — and one habit: measuring your bulkiest item before buying.

Suncast vs Keter: Dimensions Compared

The same 170-gallon class produces different footprints by brand. Suncast’s BMDB1171 is wider and taller; Keter’s is slightly narrower and shorter but rates its lid far higher.

Note the interior column: Suncast publishes it, Keter does not. Interior dimensions are what your gear touches and are always smaller than the exterior because walls, floor, and lid lip eat space. When a brand stays quiet, subtract roughly an inch from each exterior side as a working estimate.

Why 170 Gallons Doesn’t Mean One Fixed Size

Gallon ratings describe volume, not a standard footprint. Both boxes are labeled 170 gallons — Keter lists it as 643 liters — yet exterior dimensions differ enough that a replacement lid or custom cushion sized for one won’t fit the other.

Long rigid items expose this fastest. A 55-inch garden stake or rolled rug fits a 56-inch interior width easily but fails in a box closer to 54 inches. Volume never tells you that; only interior width does. The same applies to depth — pool noodles, snow shovels, and folding tables care about depth long before gallons.

Comparing models side by side? Our tested roundup of the best 170 gallon deck box options breaks down which ones hold their rated capacity in real use.

What Actually Fits Inside a 170-Gallon Box

Both brands describe the 170-gallon box as outdoor storage for cushions, garden tools, pool gear, and toys — a list that holds up against the interior numbers, with one caveat about shape. Comfortably, a Suncast BMDB1171 holds:

• Patio cushions — four to six standard seat cushions stacked flat, or two chaise lounge cushions folded once.
• Garden tools — long-handled shovels, rakes, and hoes laid diagonally or straight across the 56-inch width.
• Pool gear — inflatables, floats, and deflated pool toys with room left for towels.
• Outdoor toys — balls, ride-on cars, and sandbox sets in a single layer.
• Grill accessories — covers, tools, and a small propane tank stood upright in a corner.

What doesn’t fit well: anything longer than 56 inches, anything taller than 27 inches stood vertically, and anything you need to reach without lifting the lid past a full load. Rigid items fail by dimension, not volume — a box can be half empty and still refuse a 60-inch item.

Matching the Box to Your Gear

Measure three things before choosing: your longest item, your deepest item, and whatever you’ll stack on the lid.

Ventilation differs too — Keter’s vented lid helps damp cushions dry out, which matters in humid climates. Check replacement lids, organizers, and cushions against the exact model number, not the gallon rating, because proportions shift between brands and production runs. And if having one delivered, check your gate and doorway against the packaging footprint, not the assembled size — Suncast ships its 170-gallon box in a carton roughly 58.6 inches long and over 30 inches tall.