Plan compost deliveries with confident yardage estimates now. Handles rectangles, circles, and mixed units easily. Include waste, bag counts, and budget before buying more.
These examples show common garden scenarios. Adjust allowances to match your site and handling method.
| Scenario | Dimensions | Depth | Waste | Settling | Order Volume (yd³) |
|---|---|---|---|---|---|
| Raised bed top-up | 12 ft × 4 ft | 2 in | 10% | 15% | 0.25 |
| Lawn top-dress | 30 ft × 20 ft | 1 in | 10% | 15% | 0.75 |
| Round tree ring | 10 ft diameter | 3 in | 12% | 15% | 0.75 |
Note: Order volumes above are rounded to 0.25 yd³.
The calculator converts all inputs to feet, computes cubic feet, then converts to cubic yards.
| Rectangle area | Area = Length × Width |
|---|---|
| Circle area | Area = π × (Diameter ÷ 2)² |
| Volume | Volume (ft³) = Area (ft²) × Depth (ft) |
| Convert to cubic yards | yd³ = ft³ ÷ 27 |
| Allowances | Adjusted yd³ = yd³ × (1 + Waste%) × (1 + Settling%) |
| Rounding | Order yd³ = round up to chosen increment |
| Bag count | Bags = ceil((Order yd³ × 27) ÷ Bag ft³) |
| Weight estimate | lb = Order yd³ × Density (lb/yd³) |
Density and allowances change results significantly; use local supplier specs when possible.
For uneven sites, measure several depths and use the average.
Bulk compost is usually priced and delivered by cubic yard. Estimating volume from your bed or lawn dimensions reduces shortages, extra trips, and uneven coverage. A yard equals 27 cubic feet, so small depth changes quickly become significant across large areas. Using consistent units helps you compare quotes and plan staging space for drop offs.
Compost applications are commonly measured in inches, while beds are measured in feet or meters. Convert depth to feet before multiplying by area. For lawns, one inch is often enough for soil biology and leveling. For raised beds, two to three inches supports fertility without burying crowns. When in doubt, measure existing soil grade at several points and average.
Real sites rarely match perfect rectangles. Waste allowance covers edge trimming, wheelbarrow losses, and surface irregularity. Settling allowance accounts for compaction and moisture change after spreading. If compost is screened and relatively dry, settling can be lower. If it is wet, fluffy, or applied thickly, increase the allowance. Document your typical percentages so future projects become faster and more accurate.
Bag estimates are useful when buying retail compost or blending small additions. Converting the rounded order volume to cubic feet lets you estimate bags in common sizes like one cubic foot or forty liters. Weight depends on bulk density, which varies by feedstock and moisture. A higher density increases truck load, labor effort, and the need for ground protection on soft lawns.
Use the rounded order volume to match supplier increments, such as quarter yard or half yard. Enter price per yard and delivery fee to estimate total cost and compare vendors on an equivalent basis. Consider splitting deliveries for tight access, and schedule during dry weather to reduce rutting. Keep your calculations with job notes to support repeatable, professional estimates. This improves budgeting, reporting, and planning.
Many lawns respond well to about one inch. Use two inches for poor soil or heavy leveling. Measure several spots, average the depth, and avoid smothering grass by spreading evenly.
Waste covers edge trimming, spillage, and uneven grade. Settling accounts for compaction and moisture change after spreading. Including both helps you order closer to what you will actually place.
The tool converts your rounded cubic yards to cubic feet, then divides by your bag size. Choose common bag sizes like 1.0 cubic foot or 40 liters to estimate how many bags to purchase.
Density depends on moisture and feedstock. Use your supplier’s spec if available. If unknown, start near 1,000 lb per cubic yard and adjust after you compare results with past deliveries.
Suppliers often sell in fixed increments, such as quarter yard or half yard. Rounding up ensures you have enough material and matches how invoices and delivery tickets are typically issued.
Yes. Select metric units for length and depth, and the calculator converts internally. Mixing length and depth units is fine, as long as each field uses the correct unit selection.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.