Mulch, topsoil, decorative rock and gravel are estimated by area × depth. Sod is estimated by area plus an allowance for cuts. Use this landscape material calculator to turn your measurements into cubic yards or cubic meters, then add product details for bags, bulk ordering increments or sod pallets. Weight estimates require a matching density from your supplier.
Key takeaways
- Cubic yards = square feet multiplied by depth in inches, divided by 324.
- One cubic yard covers 324 square feet at 1 inch deep, or 108 square feet at 3 inches.
- For a mulch top-up, subtract the existing average depth from the desired finished depth, then calculate the material needed for the difference.
- Sod is area plus a cutting allowance, divided by the actual coverage of the pallet, roll, or piece.
- A weight estimate needs a density from your supplier that matches the product and its moisture condition.
Calculate your landscape materials
Choose a material and measure your area. Add supplier details when you have them to see bulk, bag or sod ordering options.
Loading the calculator. The formulas and examples below are available without the interactive tool.
Your materials estimate
Inputs and assumptions
Jump to: Mulch · Topsoil · Landscape rock · Gravel · Sod · Coverage and bag tables · Formulas
How to use the landscape material calculator
- Choose your material and U.S. or Metric units.
- Enter a rectangle, circle or known area. Add up to five non-overlapping sections if they share the same material and depth.
- Enter the thickness you plan to add. For sod, enter a cutting allowance instead of a depth.
- Open the optional ordering details if you know your bag size, bulk order increment, supplier density or sod coverage.
- Calculate, then copy, print or share the list for a conversation with your supplier.
For curved beds, divide the space into simple sections and measure each once. Use known area when you already have a measured total. Calculate separately for different materials or depths. The calculator does not subtract plants or existing objects automatically.
What the result means
Calculated volume is the space occupied at your entered depth. Volume with your allowance adds only the extra percentage you chose. The bulk option rounds that adjusted volume up to your supplier's increment. The bag option rounds it to whole bags using the size you entered. Bags and bulk are alternative ways to buy the material; do not add both quantities to the order.
A geometric volume does not automatically tell you how much loose material will deliver a particular finished depth after settling or compaction. Ask your supplier whether a volume adjustment is needed. If you enter one, its percentage is extra relative to the calculated volume. A weight estimate also needs a density appropriate to that adjusted volume, product and moisture condition.
Mulch calculator: how much mulch do I need?
For a new mulch layer, multiply square feet by depth in inches and divide by 324 to get cubic yards. A 20-foot by 10-foot bed at 3 inches deep needs 50 cubic feet, or about 1.85 cubic yards, before extra material. If your bags contain 2 cubic feet, that is 25 bags. If your bulk supplier sells in half-yard increments, the bulk option is 2 cubic yards.
These are example inputs, not a depth recommendation for every planting bed. Appropriate mulch depth depends on the material and planting conditions. The University of Maryland Extension guide to mulching trees and shrubs explains the risks of excessive mulch and the importance of keeping it away from trunks.
How much mulch do I need to top up an existing bed?
Subtract the current average depth from your desired total depth, then calculate only that difference. For the same 200-square-foot bed, increasing an average depth from 1 inch to 3 inches means adding 2 inches: about 1.23 cubic yards, or 17 whole 2-cubic-foot bags with no extra allowance. Measure several spots to estimate the current average.
If the current average depth already meets or exceeds your target, this calculation returns zero additional mulch. It does not predict future settling or assess whether the existing mulch should be removed.
Topsoil calculator: how much soil do I need?
Multiply the area by the depth of topsoil you plan to add. A 100-square-foot area with a 2-inch layer occupies about 0.62 cubic yards before a supplier adjustment. If, for this example, the supplier specifies 20% extra relative to that volume, the adjusted amount is about 0.74 cubic yards. At a quarter-yard ordering increment, the bulk option is 0.75 cubic yards.
The 20% value is illustrative; it is not a default settling factor. Soil volume and weight depend on the product and its condition. The University of Minnesota Extension explanation of soil compaction sets out how compaction changes soil pore space and bulk density, and moisture and elevation affect delivered quantities in the same way. Match any conversion to the material you are buying.
This is a material quantity estimate. Choosing a suitable soil, blending amendments and setting finished grades require separate decisions.
Landscape rock calculator: how much decorative rock do I need?
Calculate decorative rock volume from area and depth, then use supplier bulk density only if you need weight. Covering 100 square feet at 3 inches takes about 0.93 cubic yards before extra material. With an illustrative supplier density of 1.4 U.S. tons per cubic yard, that volume weighs about 1.30 U.S. tons before rounding to purchasing units.
If the same product is sold in 50-pound bags and that density applies, the bag option is 52 bags. Alternatively, a half-yard bulk increment rounds the volume to 1 cubic yard, weighing about 1.4 U.S. tons at the same density. The weight of the rounded bulk order differs from the weight of the unrounded volume.
Rock size and material affect the layer and the density. Confirm depth and density for the actual product; the example's 1.4 figure is not a universal rock conversion. One U.S. ton is 2,000 pounds. A metric tonne is 1,000 kilograms; the calculator labels them separately.
Gravel calculator: how much gravel do I need?
For gravel, area × depth gives geometric volume; supplier details convert it into an order. A 400-square-foot area at 2 inches deep occupies about 2.47 cubic yards. In an example with a 10% handling allowance, that becomes about 2.72 cubic yards. At a half-yard order increment, the bulk option is 3 cubic yards.
If the supplier confirms a density of 1.5 U.S. tons per cubic yard for that adjusted volume, estimated weight is about 4.07 U.S. tons before bulk rounding, or 4.5 U.S. tons for the 3-cubic-yard bulk option. Both the allowance and density are example inputs. This tool does not specify a compacted base design or calculate truckloads.
Metric example
For 10 square meters at 50 millimeters, geometric volume is 0.5 cubic meters. With a supplier-specified 20% extra-volume adjustment, the estimate becomes 0.6 cubic meters. If a matching density is 1,600 kilograms per cubic meter, estimated weight is 960 kilograms, or 0.96 metric tonnes. At 20 kilograms per bag, that is 48 bags. These density and adjustment values apply only to this example.
Sod calculator: how much sod should I order?
Measure the area, add your cutting allowance, then divide by the actual coverage per pallet, roll or piece. A 40-foot by 25-foot lawn is 1,000 square feet. Adding 5% for cuts produces an area order estimate of 1,050 square feet. If your supplier's pallet covers 500 square feet, buying only whole pallets requires 3 pallets, supplying 1,500 square feet.
Ask whether your supplier sells the smaller amount by area or partial pallets before choosing that whole-pallet option. Pallet coverage varies. The Sod Solutions ordering FAQ discusses an extra allowance for cuts and notes that pallet sizes differ, which is why the calculator leaves coverage blank until you enter the actual product value. Its 5% starting cutting allowance is adjustable for your layout.
Changing between pallets, rolls and pieces clears the coverage so a previous pallet size is not mistaken for roll coverage. This area estimate does not plan the placement of seams or individual cuts.
Coverage tables: cubic yards, depth and bags
How much area does one cubic yard cover?
One cubic yard is 27 cubic feet. Its geometric coverage is 324 square feet at 1 inch deep, or 108 square feet at 3 inches deep. This table excludes extra material, settling, compaction and purchase rounding. Depths are reference measurements, not installation recommendations.
| Layer depth | Area covered by 1 cubic yard |
|---|---|
| 1 inch | 324 sq ft |
| 2 inches | 162 sq ft |
| 3 inches | 108 sq ft |
| 4 inches | 81 sq ft |
How many bags equal one cubic yard?
Divide 27 cubic feet by the bag's labelled volume and round up if you must buy whole bags. Bag sizes vary; use your actual product label. For example, the Scotts product specifications list depth-specific coverage for its 2 cubic foot mulch product.
| Volume per bag | Whole bags to supply at least 1 cubic yard |
|---|---|
| 1 cu ft | 27 bags |
| 1.5 cu ft | 18 bags |
| 2 cu ft | 14 bags — 13.5 exact bag equivalents |
| 3 cu ft | 9 bags |
This table applies to labelled volume, with no extra allowance. A bag marked only in pounds or kilograms also needs a matching bulk density to convert the project's volume to bag count.
How to convert volume to weight
Weight equals volume multiplied by density. In U.S. units, multiply cubic yards by tons per cubic yard. In metric, multiply cubic meters by kilograms per cubic meter.
The number that decides everything is the density, and it belongs to the specific product in the condition it will arrive in, which is why the calculator asks you for it instead of assuming one.
The same material, wet and dry, can differ enough to change a delivery.
Ask the supplier for the density that applies to what they are sending, and make sure it matches the volume you are converting, which is the adjusted volume rather than the geometric one if you have applied an allowance.
Check which ton as well. One U.S. ton is 2,000 pounds. A metric tonne is 1,000 kilograms.
Formulas and methodology
- Rectangle area = length × width. Circle area = π × (diameter ÷ 2)².
- Cubic yards = square feet × depth in inches ÷ 324.
- Cubic meters = square meters × depth in millimeters ÷ 1,000.
- Mulch top-up depth = desired total depth − current average depth, with a minimum of zero.
- Adjusted volume = calculated volume × (1 + extra percentage ÷ 100).
- Whole bags = adjusted volume ÷ labelled volume per bag, rounded up; or adjusted volume × matching density ÷ labelled weight per bag, rounded up.
- Bulk option = adjusted volume ÷ supplier increment, rounded up, then multiplied by that increment.
- Sod with cuts = measured area × (1 + cutting percentage ÷ 100). Whole sod units = that result ÷ product coverage, rounded up.
Structure Studios developed this calculator and its worked examples. Formula checks use independently derived reference values, including purchasing boundaries and U.S./Metric conversions. The calculator retains unrounded quantities internally and rounds purchasing options upward; displayed volume estimates are shortened for readability. It does not add allowances or bags automatically beyond the inputs shown.
Conversions follow the NIST reference values: the international foot at 0.3048 meters, the inch at 0.0254 meters, and the pound at 0.45359237 kilograms. A cubic yard is 0.764554857984 cubic meters.
Before placing your order
- Check measurements and avoid counting shared sections twice.
- For mulch top-ups, subtract the existing average depth rather than buying the full target layer again.
- Confirm whether an entered depth describes the material before or after settling or compaction. Obtain any required volume adjustment from the supplier.
- Use the actual bag size, sod coverage and density. Neither a pallet nor a ton represents a universal coverage area.
- Compare the bulk and bag options as alternatives, and confirm availability and rounding with the supplier.
This calculator provides a preliminary materials estimate. It does not replace an installation plan, site assessment or supplier confirmation of quantities and product suitability.
Related Calculators
Working out a different number on the same project? Use our Paver Calculator for pavers, base and jointing sand, our Landscape Grading Calculator for slope and cut and fill, and the Pool Gallon Calculator for water volume.
Frequently Asked Questions
No. The calculator doesn't import into VizTerra, so use its numbers next to your project. In VizTerra, you can use Smart Data to pull area, perimeter, hardscape materials, and plant counts from the design itself, and those quantities update whenever the design changes.
Turn the materials estimate into a landscape your client can see
Every number in an estimate traces back to a design decision. Widen a planting bed and the mulch order grows; swap a gravel path for sod and the delivery changes with it.
In VizTerra, you make those decisions inside the design. You draw the layout in 2D and continue designing planting and materials in 3D. Along the way, you can use Smart Data to pull hardscape and deck material calculations and plant counts straight from the project, and they update whenever you change the design.
The calculator is a separate tool for loose materials such as mulch and gravel, worked out from the area and depth you enter. It doesn't import into VizTerra, so keep its results alongside your project.
Once you've walked your client through the whole outdoor living space in 3D, they can see how lawn areas, planting beds, and hardscape work together and give clearer feedback before anything is ordered. Every line on the estimate then reflects a decision you made together.
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