Pergola Calculator
— How Much Do You Need?

Building a pergola involves a lot more than lumber and hardware. The ground underneath and around your structure needs the right aggregate foundation to look polished, drain properly, and stay stable over time. Hello Gravel delivers bulk crushed stone, road base, pea gravel, fill dirt, topsoil, crushed concrete, and other landscaping aggregates by the truckload, so you can cover every layer of your project from a single supplier. Whether you need to fill in low spots before you set your posts, build up a solid compacted base layer, or finish the surface with clean decorative gravel, we have materials to fit every phase of the job. You place your order online, pick your delivery date, and one of our vetted local haulers brings the material straight to your property. Free dump truck delivery, clear upfront pricing, and no surprises.

Base gravel and decorative gravel serve two completely different purposes, and a well-built pergola patio almost always benefits from having both. Base gravel, often called crusher run, road base, or dense-grade aggregate, is a blend of crushed stone and fine particles that lock together tightly when compacted. This creates a firm, stable foundation layer that resists shifting, supports weight, and allows water to drain through rather than pool beneath your structure. Think of it as the part nobody sees but everybody relies on. Decorative gravel sits on top of that compacted base. It is clean, loose, and selected for how it looks and feels underfoot. It does not compact the same way base material does, but it gives your space the finished, polished appearance that makes a pergola patio feel like a real outdoor room. For a pergola patio built from scratch, most landscapers recommend 4 inches of compacted base material as the foundation, topped with about 2 inches of decorative gravel on the surface. If you already have a solid, stable base in place and are just refreshing the look, you may only need to order a topdress of decorative material. Not sure what you have or what you need? Use the Hello Gravel calculator or reach out to our team and we can help you figure out the right combination before you order.

Pea gravel is one of the most popular choices for the finished surface under a pergola, and it earns that reputation. Its smooth, rounded shape is comfortable underfoot, which matters a lot if you plan to spend time in that space barefoot or with kids around. It drains extremely well, comes in warm natural earth tones, and gives outdoor living spaces a relaxed, inviting feel. Standard pea gravel typically runs about 3/8 to 1/2 inch in size and holds up well in most climates. Crushed stone is a strong alternative if you want a crisper, more angular look. The irregular edges interlock just enough to keep the material from shifting as much as pea gravel does, which makes it a practical choice if you plan to set patio furniture directly on the surface or if the space sees heavier foot traffic. Decomposed granite is another option worth considering. It compacts down to a smooth, sand-like surface that feels more like a solid patio than a loose gravel bed, which some homeowners prefer under a pergola used for dining or entertaining. The right choice ultimately comes down to how you plan to use the space and what look fits your yard. If you are weighing your options, reach out to the Hello Gravel team and we can help you find the right material based on your region and project goals.

For a full pergola patio build starting from bare ground, the standard recommendation is 4 inches of compacted base material as your foundation layer, followed by approximately 2 inches of decorative gravel on the surface. That 4-inch base depth is the key to long-term stability. It gives you a well-drained, firm foundation that resists the kind of settling and shifting that happens when base material is too thin, especially in climates that experience freeze-thaw cycles. As a general starting point, 1 ton of gravel covers roughly 100 square feet at 2 inches of depth. At 4 inches of depth, that same ton covers about 50 square feet. To put that in real terms: a 12x16-foot pergola footprint covers 192 square feet. At 4 inches of compacted base depth, you are looking at approximately 4 tons of base material for that area, plus around 2 tons of decorative gravel at a 2-inch finish depth. Your actual needs will vary depending on your existing soil conditions, how much excavation is involved, and whether any grading or filling is required before you start layering. These figures are meant to give you a reasonable ballpark, not a final order number. For an accurate estimate based on your exact project dimensions, use the Hello Gravel calculator on our website. It takes less than a minute and gives you a tonnage figure you can order with confidence.

Good ground prep is what separates a pergola patio that looks great for years from one that sinks, shifts, or turns into a weed problem within a season or two. Taking the time to do this step right makes everything that follows much easier. Start by excavating the area to the appropriate depth. If you are planning to lay a 4-inch base layer plus a 2-inch decorative top layer, you need to dig down roughly 6 inches from your finished grade, plus a little extra to account for tamping and settling. Remove all grass and organic material from the excavated area. Organic matter breaks down over time and causes the ground to sink, which is the last thing you want under a gravel patio. After excavating, grade the area so there is a gentle slope away from your pergola posts and any adjacent structures. Even a 1-inch drop over 8 feet of run is enough to move rainwater away and prevent pooling. Once graded, tamp the native soil firmly before you add anything on top. Many homeowners then lay landscape fabric directly on the tamped soil before the first layer of gravel goes down. It allows water to drain freely while blocking weed growth from below. If your yard has significant low spots or uneven terrain that needs to be brought up before grading, fill dirt is the right material to start with. Hello Gravel delivers fill dirt by the truckload in addition to gravel, so you can handle the entire project with one supplier and one delivery window.