Topsoil Calculator

1. Enter the area to cover in square feet (length times width).
2. Enter the depth of the topsoil layer in inches.
3. Pick a bag size if you are buying bags, and a density override if your supplier gives one.
4. Choose an overage and read the cubic yards, weight and bag count.

Here is what each result line means:

Topping beds with mulch too? Pair this with the mulch calculator.

A topsoil calculator is a material estimator for soil. It turns the area and depth you want to cover into a volume in cubic yards, a rough weight in tons and a count of bags, so you can order in bulk or by the bag.

Topsoil is the fertile upper soil layer used to build lawns, level low spots, fill raised beds and topdress turf. Suppliers sell it by the cubic yard in bulk and by the bag in cubic-foot sizes.

It uses the same area-and-depth method as the mulch and coverage calculators.

The divisor 324 folds 12 inches per foot and 27 cubic feet per cubic yard into one step (12 x 27 = 324). For bags, the volume in cubic feet is divided by the bag size.

1. Cubic yards = area in square feet times depth in inches, divided by 324.
2. Bags = the volume in cubic feet divided by the bag size, rounded up.
3. Weight = cubic yards times the density, about 1.15 tons per cubic yard dry.

A cubic yard is 27 one-cubic-foot bags, so bags add up fast. Above about a cubic yard, bulk delivery is far cheaper than bags.

A 500 sq ft lawn at 4 in of topsoil.

Calculation: Volume = 500 x 4 / 324 = 6.17 cubic yards, about 6.8 with a 10 percent overage. That is roughly 7 tons, or over 180 one-cubic-foot bags, so bulk delivery makes sense.

A 4 x 8 ft raised bed at 10 in is 32 x 10 / 324 = 0.99 cubic yards, about 27 one-cubic-foot bags.

Depth and Job

Depth sets the volume. Topdressing is a fraction of an inch, a new lawn 4 to 6 inches, a raised bed 6 to 12. The job decides the depth.

Moisture

Moisture is the biggest weight variable. Wet topsoil can weigh 20 percent more than dry, so a weigh-ticket can read heavier than the estimate.

Bulk vs Bags

A cubic yard is 27 one-cubic-foot bags. Bags suit a small bed; bulk by the yard is far cheaper above a cubic yard.

Settling

Loose topsoil settles after watering, so add about 10 percent and expect a new bed to drop a little.

Screened vs Fill

Screened topsoil is cleaner and a bit lighter than unscreened fill soil; use the supplier density when you have it.

Typical depths by job and how bag counts scale with bag size.

A new lawn wants 4 to 6 inches, topdressing a quarter to half inch, and a raised bed 6 to 12 inches. Check the cubic-foot rating printed on the bag, since it varies by brand.

New Lawns

Size the topsoil for a new lawn before seeding or laying sod.

Raised Beds and Gardens

Fill a raised bed or garden to depth, often blended with compost.

Topdressing

Work out a thin topdressing layer to level and feed an existing lawn.

Grading and Fill

Estimate soil to level a low spot or build up a grade.

Checking a Delivery

Compare a bulk ticket in cubic yards against the area and depth you filled.

1. Using /27 with Inches

The 27 divisor needs depth in feet. With inches, divide by 324, or convert the depth to feet first.

2. Buying Bags for a Big Job

A cubic yard is 27 one-cubic-foot bags. For several yards, bulk delivery is far cheaper and quicker.

3. Too Shallow for Turf

A new lawn wants 4 to 6 inches of topsoil; a thin skim over hard subsoil grows poorly.

4. Ignoring Settling

Fresh topsoil settles after watering. Add about 10 percent and top up beds later.

5. Mixing Feet and Inches

Depth is in inches here. A 4 inch layer is 4, not 0.33.

6. Ignoring Moisture on Weight

Wet topsoil weighs more, so a dry density understates a damp delivery.

The calculator estimates volume, weight and bag count from area, depth and density.

Multiply the area by the depth in inches, divide by 324 for cubic yards. A 500 sq ft lawn at 4 in is about 6.17 cubic yards, roughly 7 tons, or over 160 one-cubic-foot bags.

About 27 of the 1-cubic-foot bags, 36 of the 0.75-cubic-foot (40 lb) bags, 18 of the 1.5-cubic-foot bags, or 14 of the 2-cubic-foot bags.

About 1.15 tons for dry, loose topsoil, rising toward 1.5 when wet or compacted. Moisture is the biggest variable.

About 4 to 6 inches for a new lawn so roots can establish; a turf minimum is often 6 inches. Topdressing an existing lawn uses only a quarter to half inch.

Use the bed footprint times 6 to 12 inches. A 4 by 8 ft bed at 10 inches is about 1 cubic yard, or 27 one-cubic-foot bags.

Bags suit a small bed up to about a cubic yard. Beyond that, bulk delivery by the yard is far cheaper than hauling dozens of bags.

At 1 inch deep, a cubic yard covers about 324 square feet; at 3 inches, about 108; at 6 inches, about 54.

Yes. Wet or damp topsoil can weigh around 20 percent more than dry, so a delivery billed by weight reads heavier than a dry estimate.

Topsoil is the fertile upper layer for growing; fill dirt is subsoil for building up grade and does not grow plants well. They have different uses and prices.

No. The calculator runs entirely in your browser and nothing is stored or sent.

• Inch Calculator – Topsoil / Soil Weight (Topsoil density and cubic-yard math.)
• CalculatorSoup – Topsoil Calculator (Bag sizes and bags per cubic yard.)
• Utah State University Extension – Soil for Lawns (Topsoil depth guidance for turf and beds.)