How to Choose a 170 Gallon Deck Box | Fit, Strength & Materials

Choosing a 170-gallon deck box starts with the exterior footprint, which varies by brand, so measure twice before you buy.

One seller’s 170-gallon box can be several inches wider or deeper than another’s, so the “170 gallon” label tells you the storage class, not the physical size. Matching the exterior dimensions to your patio space, checking lid strength, and confirming the materials suit your climate are the three decisions that get you the right box the first time. The table below shows how current mainstream models from Suncast, Lifetime, and Keter compare.

Why the Exterior Footprint Comes First

The dimensions that matter most are the ones on the outside. A box that is too wide for its spot under a window or too deep for the porch will be a return headache, not a storage win.

Current U.S. models in the 170-gallon class show meaningful variation. Suncast’s 170 Gallon Extra Large Deck Box measures 58 inches wide by 29.25 inches deep, while the Lifetime 170-Gallon model is 61.6 inches wide and 27.9 inches deep. That’s a difference of 3.6 inches in width alone. Measure the intended space, including clearance for the lid to open fully, before you settle on a brand.

You also want to think about how the box will be used. A 170-gallon deck box holds roughly 20 to 23 cubic feet of gear, which is plenty for patio cushions, pool supplies, or garden tools. If you plan to store long-handled tools, check the interior length rather than just the total capacity.

Lid Load Rating and Material Durability

Not every 170-gallon deck box is built to be sat on. Check the manufacturer’s stated lid load rating before anyone uses it as a bench or side table.

Suncast explicitly rates its 170-gallon model’s lid for 300 pounds, which makes it a safe seat for most adults. Lifetime and Keter do not publish a comparable seating rating for their 170-gallon boxes in the current specs, so treat those lids as storage surfaces only unless their documentation says otherwise. The rule is simple: no stated rating, no sitting.

Material matters for longevity. All three brands build with resin-based plastic, which resists rust, rot, peeling, and fading better than wood or metal. Keter’s 170-gallon model also features a ventilated design, which helps air circulate so stored cushions and fabric stay drier and less musty over a humid season. If your box sits in full sun, look for UV-resistant resin and a color that won’t show fading.

Before you finalize your pick, see our curated list of top-rated 170-gallon deck boxes on the market today.

Comparing the Mainstream Options

Here’s how the three trusted models stack up on the specs that affect your buying decision.

Capacity differences exist even within the same class. Lifetime’s 174.2-gallon interior is slightly larger than the nominal class, and its interior floor space of 10.6 square feet is generous for bulky items. Suncast’s interior width of 56 inches gives you long runs for tools. For cushions and pool floats, Keter’s airflow is the differentiator.

Common Mistakes to Avoid

The most frequent error is trusting the gallon figure blindly. Because the label isn’t a universal standard, always compare cubic feet and exact dimensions. A box that claims 170 gallons but measures narrower inside will hold fewer bulky items than a competing model with the same label.

A second mistake is skipping the location check. Resin boxes are heavy once loaded, so moving one across a deck after it’s full is a two-person job. Position it where you want it, on a level surface, before filling it.

Finally, don’t assume weather resistance means waterproof. These boxes are weather-resistant, meaning they handle rain and sun, but standing water or extreme pooling can still get inside. Check the lid seal and consider a slightly elevated spot if your deck floods in heavy storms.