Fill Dirt Volume Calculator

What the Fill Dirt calculator computes

Fill Dirt is the bulk-fill material used to raise grade, fill low spots, and build up volume below the planting layer. The calculator takes the area to fill in square feet and the depth in inches and returns cubic yards needed. Fill Dirt is generally sold by the cubic yard rather than by the ton because moisture content varies more in fill than in screened topsoil, and the price-per-yard is the rate suppliers actually quote.

Common fill projects: filling a swimming pool that has been demolished (30 to 80 yards depending on pool size), raising grade against a foundation for proper drainage (5 to 15 yards), filling under a deck or shed pad (3 to 10 yards), building up a yard low spot (5 to 20 yards). The cubic-yard scale matters for the conversation with the supplier; truck capacity sets the delivery economics.

The calculator output assumes compacted final volume. Fill Dirt settles 10 to 20 percent under its own weight and seasonal rain over the first year. Add 15 to 20 percent overage on any fill job to compensate, or plan a top-up at the one-year mark.

Fill Dirt versus Topsoil and when each applies

Fill Dirt and Topsoil are different products with overlapping appearances. Fill Dirt is bulk subsoil dug from grade-correction projects, stockpiled, and resold. It contains stones, clay clumps, and root fragments. It is mineral soil with little organic content, which makes it appropriate for structural fill but useless as a planting medium.

Topsoil is the screened organic-rich surface layer, with 5 to 10 percent organic content and a fine uniform texture after screening. It supports plant growth.

Use Fill Dirt for any application below the visible grade where plants will not grow. Foundation backfill, low-spot correction, under-deck fill, demolished-pool fill, under-shed-pad fill. The volume is large; the appearance does not matter; the price is low ($18 to $32 per cubic yard delivered).

Use Topsoil for the top 4 to 6 inches where plants will grow. Lawn renovation, garden beds, sod prep. The volume is smaller; the appearance and quality matter; the price is higher ($32 to $55 per yard).

For grading projects, the cost-efficient pattern is Fill Dirt for the bulk volume below the planting layer, then 4 to 6 inches of Topsoil on top for the visible finish.

Compaction for structural fill

Any fill that will support a structure (driveway, sidewalk, deck pad, shed slab, retaining wall) requires compaction. Uncompacted Fill Dirt settles 10 to 20 percent over the first two years, which produces driveway ruts, cracked patios, and sloping decks. Compacted fill achieves 90 to 95 percent of natural soil density and behaves like undisturbed soil.

The compaction sequence is: place fill in lifts of 8 to 12 inches at a time, run a plate compactor or vibratory roller in overlapping passes across the lift, repeat for the next lift. Larger jobs (over 50 yards) use a ride-on roller or a sheepsfoot compactor on rented equipment; smaller jobs work fine with a rental plate compactor.

For fill that will NOT support a structure (yard low spots, landscape berms, planting beds), light compaction by walking on it and watering it in is enough. Heavy compaction is overkill and actually hurts plant root penetration in landscape applications.

Delivery logistics for large fill projects

Fill Dirt orders are typically larger than other aggregate orders, which changes the delivery format. A swimming-pool fill at 60 yards needs three tri-axle truck loads; a foundation-grade-correction at 8 yards rides on one tandem-axle truck. Sequence the trucks 2 to 3 hours apart so you can spread the first load before the second arrives, otherwise the trucks pile up and the unloading takes all day.

For large fill projects, consider hiring a skid-steer with a bucket or a small tracked loader from a rental yard ($200 to $400 per day). The machine spreads the fill in roughly 1/10th the time of hand-shoveling. For under 5 yards total, hand-spreading with shovels and wheelbarrows is fine for one person in a half-day.

Stage the pile somewhere it can sit without becoming a problem. Fill Dirt on grass kills the grass within hours; on a driveway it tracks mud into the house every time someone walks past. Tarps under the pile are mandatory unless the drop is on a dedicated dirt or gravel area.

Common fill project mistakes

The biggest mistake is using Fill Dirt where Topsoil is needed. Filling a planting bed with cheap fill saves money up front and costs three growing seasons of failed plantings. The plants establish poorly, the soil drainage is wrong for root growth, and the bed ends up dug out and refilled with proper Topsoil anyway. Always cap fill projects with the planting-grade layer.

The second mistake is no compaction on structural fill. The fill goes in, the deck or pad gets built, and within a year the corner of the structure has settled an inch. By year three the structure is unusable and the fill has to be excavated, recompacted, and the structure rebuilt. Compact in lifts; spend the day on the rental compactor.

The third mistake is too much fill against a foundation. Backfill grade should slope away from the foundation at 5 percent for the first 10 feet (6 inches of drop). Fill that builds up against the foundation higher than 6 inches below the siding line invites water and pests into the structure. Use the volume math to verify you are not over-filling the foundation perimeter.

Permits, grading, and lot drainage rules

Large fill projects often trigger local grading regulations, especially in jurisdictions with strict stormwater management requirements. Threshold rules vary widely. Some municipalities require a permit for moving more than 10 cubic yards of fill on a residential lot. Others allow unlimited residential fill but require a permit when fill changes the lot drainage pattern. A few require a soil erosion and sediment control plan for any fill over 50 yards.

Check the local code office before ordering large fill quantities. The cost of a typical residential fill permit is $50 to $200; the cost of getting caught moving fill without one is a $500 to $5,000 fine plus restoration. Permit application turnaround in most municipalities is 1 to 3 weeks.

Drainage matters too. Fill that changes how water flows on the lot can divert runoff onto neighbors, which creates legal liability. The general rule: keep stormwater on your own property by grading fill to drain into infiltration areas (lawn, beds, dry wells) rather than toward property lines. For larger fill projects, mark planned drainage paths on a sketch before ordering and verify the grade with stakes and a string line as the fill goes in.

For very large fills (over 100 yards) or fills changing grade by more than 2 feet, retain a civil engineer to verify the grading plan. The $500 to $1,500 design fee prevents the larger costs of post-construction drainage problems.