Topsoil Calculator

Turn your site sketch into cubic yards

Multiply each surface by its planned layer depth, repeat matching areas by quantity, then add the group volumes. The raw total answers the geometry question. Your allowance creates a separate shopping figure.

A rectangular area uses length × width. A circle uses π × radius², where radius is half the measured diameter. A surveyed lawn or an irregular shape can use the known-area option. In imperial mode, depth in inches is divided by 12 to make feet before volume is calculated. In metric mode, centimeters are divided by 100 to make meters.

One cubic yard contains 27 cubic feet. GardenMeasure follows the NIST conversion factors. It keeps full precision until the displayed result. Bag count works differently because shops sell whole packages, so the final count rounds upward.

Map the ground before you price the topsoil

Walk the job with a tape and a rough sketch. Record each shape, usable dimensions, intended depth, and every section that will not receive soil. Ten careful minutes here can prevent a second delivery.

Measure rectangles at soil level. For a circle, pull the tape straight through the center to find diameter. Entering a radius in the diameter field cuts the calculated area to one quarter of the correct size. Use quantity only for sections with matching dimensions and depth.

Split an L-shaped lawn into two rectangles that touch without overlapping. Approximate a curved border with short sections. If a survey already states the planted square footage, use known area instead of inventing a length and width.

The irregular-bed field guide compares split shapes, repeated widths, average radius, and mapped area before you choose the known-area input.

On a slope, take readings across high and low points. Either use a written working average or calculate the shallow and deep zones as separate groups. The calculator cannot see tree roots, edging, humps, or an old pile already on site. Put those facts on the sketch.

Choose a depth for this site, not an average garden

Your site plan, existing soil, grade, and planting goal should set the topsoil depth. A lawn repair, new border, and deep raised bed solve different problems, even when a search result calls all three “topsoil projects.”

Topdressing an established lawn is a different job from filling a new planting bed. A thin layer changes volume dramatically across a large area, while a deep new bed needs far more material. For example, 1,000 square feet at one inch is about 3.09 cubic yards; the same area at six inches is about 18.52 cubic yards. Depth is therefore the measurement worth checking twice.

For a worked ordering example, 1,000 square feet at two inches requires 6.17 cubic yards before allowance. A user-chosen 10% allowance changes the planning figure to 6.79 cubic yards. If the supplier sells only in half-yard increments, the next available order is 7 cubic yards. If a chosen bag holds 0.75 cubic foot, the same adjusted volume requires 245 whole bags. These are two ways of packaging the same volume, not universal recommendations about project depth or allowance.

Soil suitability also matters. Topsoil is not a standardized bag of identical particles: texture, organic matter, contaminants, screening, stones, moisture, and nutrient status can vary by source. Ask what the supplier's product contains and whether test results are available. The University of Maryland Extension advises considering the source and quality of material used to fill raised beds, especially where contamination is a concern.

Use the topsoil, garden soil, and compost comparison when the project still needs a material decision. Return here after you confirm that topsoil is the correct fill.

If the project needs a complete soil fill rather than only topsoil, compare the general Soil Calculator. If the goal is an organic amendment layer, use the Compost Calculator instead. Naming the actual material keeps ordering math connected to the intended job.

Compare the invoice, not the advertised unit price

Put both options on the same basis: enough volume for the job, whole bags where required, and every delivery charge. The cheapest price per yard can lose once a small-load fee appears.

Bags can suit small projects, constrained access, staged work, and places where a bulk pile cannot be tipped safely. Bulk can reduce packaging and handling for a larger project, but minimum order quantities, delivery zones, truck access, taxes, and unloading rules can change the quote. Those are supplier terms, not geometry, so confirm them directly.

Bag count uses volume, not the weight printed prominently on some packages. A 40-pound bag does not reveal a universal cubic volume because moisture and density differ. Find the package's volume statement, such as cubic feet or liters, and enter that number. The calculator rounds up after the order allowance, which can make the purchased bag volume slightly exceed the target.

Use the mulch and soil bag-size guide when packages use cubic feet, dry quarts, or liters and need a consistent unit-price comparison.

The bulk comparison does not automatically round to a supplier's minimum increment. If a yard sells only in half-yard steps, round the displayed cubic yards to the next available increment and ask for that real quote. This prevents a precise-looking estimate from pretending to be the supplier's final invoice.

At what volume does bulk beat bags?

Bulk wins only after the order is large enough to repay the delivery fee.

Break-even bags = delivery fee ÷ (price per bag − bag volume × bulk price per cubic yard), rounded up to whole bags. Break-even volume = break-even bags × bag volume. Below that volume, whole bags cost less. Above it, bulk delivered costs less. The calculator works this out live from your prices above.

Supplier minimums, half-yard increments, taxes, and delivery zones are not in this sum. Confirm them with the supplier before ordering.

Use the supplier's density before you discuss tons

Volume × bulk density gives estimated weight. Leave density blank until the seller provides a figure for the product and moisture condition you expect to receive.

Topsoil weight changes with mineral texture, organic content, screening, compaction, and especially moisture. A fixed internet estimate may be reasonable for a rough conversation yet wrong for a vehicle payload or supplier invoice. GardenMeasure therefore refuses to invent a default tonnage. When density is entered, the tool labels the output as an estimate tied to that assumption.

Do not use this estimate to approve towing, axle loads, retaining structures, or other safety-critical decisions. Confirm actual material weight and legal vehicle limits with the supplier, carrier, and vehicle documentation. Volume planning answers “how much space”; it does not certify how safely that material can be transported.

The tool reports short tons when imperial density is used and also shows kilograms. A short ton is 2,000 pounds. A metric tonne is 1,000 kilograms and is not identical to a short ton. Keeping those labels explicit prevents a surprisingly expensive unit mix-up.

The cubic-yard soil weight guide works one example through in full: at 72 pounds per cubic foot, one cubic yard weighs 27 × 72 = 1,944 pounds. The same guide shows moisture adding 15 percent of dry mass in its example, taking 1,944 pounds to 2,235.6 pounds. Those are worked examples for one stated condition, not a weight for your topsoil. The calculator repeats the same two figures for your volume in the result above, labelled as an illustrative example.

How much extra topsoil should you order?

Use an allowance only for a reason you can name: measurement uncertainty, uneven grade, supplier handling, or expected settling. The calculator accepts zero and shows both raw and adjusted totals.

A percentage is not a gardening law. Ten percent is a common planning choice, but a surveyed rectangular site and a loose curved border do not have the same uncertainty. If measurements are reliable and a supplier sells small increments, a smaller allowance may be enough. If the ground is uneven, improving the measurements is better than covering a large unknown with a random percentage.

Before paying, write down the areas, depth, raw volume, allowance, adjusted volume, bag size, and bulk quote. Ask the supplier to confirm whether the product is sold loose, compacted, screened, or by a nominal bucket. A transparent estimate makes that conversation quick because every assumption is visible.