Topsoil Calculator: How Much Topsoil Do I Need?

How much topsoil do I need?

To work out how much topsoil you need, measure the area you are covering, choose a depth, then multiply the two to get a volume - and convert that volume into cubic yards, tons or bags so you can order the right amount. The calculator above does it instantly; this is the formula it runs:

The 324 is 27 cubic feet per cubic yard multiplied by 12 inches per foot, so it converts feet, inches and yards in one step. Depth moves the final number more than area does — the depth table below sets out what each job needs.

How to use this topsoil calculator

1. Measure the area. Length and width in feet. Split an irregular shape into rectangles and add them up. No tape? An adult stride is roughly 2½ to 3 feet.
2. Pick the depth. Use one of the presets, or see the depth table below.
3. Read the result. Cubic yards is what a soil yard will ask for; tons is what a supplier selling by weight quotes; bags is what you would buy at a garden center.

Worked examples

New lawn from seed — 40 ft × 25 ft

One dump-truck delivery. Order 14 yards and keep the extra for the inevitable low spot.

Topdressing an existing lawn — 1,500 sq ft

Right on the bulk/bag border. If the truck can reach the driveway, take it in bulk.

Filling a low spot — 8 ft × 6 ft, 3 in deep

Well under any delivery minimum. Buy bags, and fill in two passes of 1½ inches rather than one of three.

Bags, bulk or a truck?

Once you have a figure, the volume itself decides how you should buy it.

How deep should topsoil be?

Depth drives the final number more than area does. Too thin and roots never leave the old ground; too thick over an existing lawn and you smother the grass you are trying to help.

Filling a raised bed or planter instead of covering ground? That is container volume, not area × depth — the soil calculator handles bed and pot sizes and returns bag counts.

Topsoil coverage by depth

One cubic yard of topsoil covers 324 square feet at 1 inch deep. Every figure below is 324 divided by the depth.

Topsoil for a new lawn, sod and bare patches

From seed. Spread screened topsoil over the graded area, rake it level, water it in, then sow. The grass seed calculator works out how much seed that area needs. If the existing soil is already reasonable, 2 inches worked into the surface does more for the grass than 4 inches sitting on top of compacted clay.

Before sod. Sod arrives with about an inch of soil attached, but still needs the same bed underneath to root into — raked dead level so the seams sit flat. Sod vs. seed covers the cost and timing trade-offs.

Bare patches. A thin layer, enough to give seed something to sit in. Loosen the surface, spread, sow, keep it damp — a handful of spots is a bags job, not a delivery job. Fall is the best time to do it.

Topsoil for leveling and topdressing

These two get confused constantly, but they are different jobs. Topdressing covers the whole lawn in a thin layer; leveling puts soil only where the ground dips.

Topdressing goes across the whole lawn, raked in until the grass shows through again. Thin enough that a 1,000 sq ft lawn takes only about 1.5 cubic yards — a bags job.

Leveling targets the dips instead. Fill in passes of no more than ½ inch at a time, letting the grass grow back between passes — grass buried under two inches in one go usually dies, and then you are reseeding a bare patch on top of the job you started. For one deep hollow, measure that hollow on its own.

How much does a yard of topsoil weigh?

Roughly 2,000 to 2,200 pounds — about one US ton. The spread is wide because weight depends almost entirely on how wet the soil is and what is mixed into it.

Published figures run from about 1,500 lb for very dry screened soil to 3,000 lb saturated. The same yard after a dry week and after a week of rain can differ by 500 pounds — which matters both for what a supplier selling by the ton charges you, and for what your vehicle can legally carry.

How many bags of topsoil are in a cubic yard?

A cubic yard is 27 cubic feet, so the bag count depends on bag volume — not the weight printed on the front.

The common big-box bag is 40 lb holding about 0.75 cubic feet, so 36 fill a cubic yard. You will sometimes see 50 quoted — that comes from dividing 2,000 lb by 40 lb, which assumes bagged and bulk weigh the same per cubic foot. They do not: bagged topsoil is drier and lighter. Go by volume.

How much does topsoil cost, and how does it arrive?

A typical residential delivery of 3–10 cubic yards lands around $150–$600 all in. Prices vary enormously by region — treat these as a sense of scale, not a quote.

What fits in a truck

Weight is the limit, not bed volume — a 16-yard body may only legally carry 12 or 13 yards of wet topsoil. Before it arrives, decide exactly where the pile should go — as close to the work as the truck can safely reach.

Topsoil vs. fill dirt, garden soil and compost

Four materials, four prices, four different jobs. A load of fill dirt where you wanted topsoil is not something you can fix with a rake.

Building up a base for a shed, path or patio rather than a growing layer? That is gravel rather than soil, and the gravel calculator works in the same yards, tons and bags.

Screened vs. unscreened. Screened topsoil has been run through a ½ or ¾ inch mesh to pull out stones and roots, so it rakes level and spreads evenly. Unscreened is cheaper and fine buried under a deeper fill. For a lawn, screened is worth the difference — or run a cheaper load through a rolling garden sifter yourself and keep the stones for drainage. Most yards will also sell a blend of roughly 70–80% topsoil to 20–30% compost — usually the better buy for a new lawn or bed. If you already have your own, work the compost in rather than laying it on as its own layer.