How much compost do I need?
Measure the area in square feet, enter depth in inches, and convert to cubic yards. A 300 sq ft area at 4 inches deep is about 3.70 cubic yards before waste.
Settling and final grade
Soil, topsoil, compost, and fill dirt can settle after placement. Deep fills and raised beds often need extra material compared with a thin topdress.
Bulk delivery vs bags
Bulk soil is often ordered by cubic yard, while bagged soil is sold by cubic feet or quarts. Convert units before comparing prices.
Compost is usually an amendment
Compost is often spread as a thinner amendment layer or mixed into existing soil rather than used as the only deep fill material.
Paver base example estimates
Examples are before waste. Keep base material and leveling sand as separate estimates.
| Project example | Area and base depth | Cubic yards |
|---|---|---|
| Small walkway | 120 sq ft at 4 in | 1.48 cu yd |
| Patio | 240 sq ft at 4 in | 2.96 cu yd |
| Large patio | 400 sq ft at 4 in | 4.94 cu yd |
| Thicker base area | 240 sq ft at 6 in | 4.44 cu yd |
Paver base coverage by depth
Coverage assumes 1 cubic yard, which is 27 cubic feet. Waste, compaction, settling, and irregular grade are not included.
| Depth | Coverage from 1 cu yd | Coverage from 2 cu yd |
|---|---|---|
| 1 in | 324 sq ft | 648 sq ft |
| 2 in | 162 sq ft | 324 sq ft |
| 3 in | 108 sq ft | 216 sq ft |
| 4 in | 81 sq ft | 162 sq ft |
| 6 in | 54 sq ft | 108 sq ft |
| 12 in | 27 sq ft | 54 sq ft |
Before you calculate
- Measure the area to be covered, then choose the compacted depth you actually need.
- Calculate driveways, paths, drains, and base layers separately when depths differ.
- Use density inputs only when converting volume into tons or weight.
Common mistakes
- Ordering by tons without checking the supplier's density assumption.
- Forgetting compaction for base layers.
- Combining decorative top rock and structural base rock into one estimate.
Formula
cubic yards = (area * (depth / 12) / 27) * (1 + wastePercent / 100)
Assumptions
- Depth is entered in inches.
- Measure separate zones when material type, depth, slope, compaction, or edging changes.
- Delivery, grading, fabric, edging, disposal, and labor are separate planning items.
Example
Estimated compost bin gravel base needed (cubic yards): 0.65 cubic yards
How to calculate compost bin gravel base cubic yards
- Measure the target coverage area in square feet.
- Enter the planned finished depth in inches.
- Convert depth to feet, multiply by area, then divide cubic feet by 27 to get cubic yards.
- Add waste for uneven grade, compaction, spreading loss, or ordering increments.
- Confirm supplier units before buying, because bulk material may be sold by cubic yard, ton, or bag.
Before you buy materials
- Ask whether the supplier sells by cubic yard, ton, scoop, or bag.
- For compacted base, plan for placement and compaction rather than loose depth alone.
FAQ
What is the example compost bin gravel base cubic-yard result?
Use area, installed depth, cubic-foot to cubic-yard conversion, and waste, then calculate the planning result. In the default example, the result is 0.65 cubic yards.
How do I calculate compost in cubic yards?
Use cubic yards = area x (depth inches / 12) / 27, then add waste or settling allowance if needed.
How much soil for a 4 x 8 raised bed?
At 12 inches deep, a 4 x 8 ft bed needs about 1.19 cubic yards before waste. At 10 inches deep, it needs about 0.99 cubic yards.
Should I include extra soil for settling?
Usually yes for deeper fills, raised beds, and loose bulk soil. Settling varies by material and moisture.
Can I compare bulk soil and bagged soil?
Yes, but convert units first. One cubic yard equals 27 cubic feet, so bag volume matters.
Does this choose the right soil mix?
No. It estimates volume. Choose soil, compost, fill dirt, or raised-bed mix based on the project.
Related calculators
This calculator is for planning estimates only. Verify final quantities with product labels, project conditions, and a qualified professional when accuracy matters.