Topsoil Calculator

Multiply the area in square feet by the depth in feet — inches divided by twelve — for cubic feet, then divide by 27 for cubic yards. A 300 square foot area at six inches works out to 150 cubic feet, or about 5.6 cubic yards. The calculator runs that for every area separately, since each one can have its own depth, adds your settling allowance on top, and converts the total into bags, cubic yards and tons so you can order in whatever unit your supplier quotes.

It depends entirely on the job. Lawn topdressing goes on thin — a quarter to half an inch at a time, since burying existing grass kills it. New planting beds generally want four to six inches of good soil. Raised beds and new lawns from seed or sod are usually filled eight to twelve inches deep so roots have somewhere to go. Structural fill and regrading are dictated by the grade you’re building to rather than a standard depth. Set each area independently in the calculator rather than averaging.

Screened topsoil generally runs somewhere around 2,000 to 2,400 pounds per cubic yard dry, and rain can add roughly a third to that because soil holds water. Sand and fill dirt are heavier; compost and lightweight garden mixes are considerably lighter. That weight is why a half-ton pickup reaches its payload limit with well under a full cubic yard — the bed will hold far more than the suspension and brakes should carry. The calculator reports tonnage and trip count for the vehicle you pick and flags loads that would be over.

Neither is inherently cheaper — they’re two ways of measuring the same pile, and which wins depends on the price pair and how heavy the material is. At roughly 2,200 pounds per cubic yard, one ton is a little under one cubic yard, so a per-ton price looks lower than a per-yard price for the same soil. Moisture matters here: you pay for water weight when buying by the ton, so a soaked pile after rain costs more per usable yard. Enter both prices and the calculator converts using your weight figure and compares the delivered totals directly. Bagged soil is almost always the most expensive per yard and makes sense mainly for small jobs or where a bulk pile has nowhere to go.

Fill dirt is subsoil sold for volume — cheap, largely inert, and used to build grade or backfill, not to grow in. Topsoil is the biologically active upper layer; screened topsoil has been run through a grid to pull out rocks and roots and is the usual choice for lawns and beds, while unscreened costs less and comes with debris. Garden or raised-bed mix is a blend of topsoil with compost and other amendments, priced well above plain topsoil but ready to plant into. A common approach is fill dirt for the bulk of a deep fill, topped with the good stuff in the root zone.

Around 10 to 20% over the geometric volume is a sensible allowance, and the deeper the fill the more you want. Soil arrives loose and full of air; watering, foot traffic and time compact it, so a raised bed filled level on delivery day sits noticeably low a few weeks later. Compost-heavy mixes settle the most as the organic matter breaks down. The calculator applies your settling percentage on top of the measured volume, and because bulk yards typically sell in half- or whole-yard increments, it rounds the order up to what you can actually buy.