10×10 ft bed at 2 in (default)
Input
10 ft × 10 ft × 2 inOutput
16.7 cu ft · 0.62 cu yd · 12 bags at 1.5 cu ft10 × 10 × 2 ÷ 324 = 0.62 cu yd. Bags: ceil(16.7 ÷ 1.5) = 12.
Compost amendment volume is **area × depth**. For US gardeners, measure length and width in feet and spread depth in inches.
**Imperial formula (rectangle):**
Cubic yards = Length (ft) × Width (ft) × Depth (in) ÷ **324**
Equivalently: Cubic feet = Length × Width × Depth (in) ÷ 12, then ÷ 27 for yards.
**Example — 10×10 ft bed, 2 in compost layer:**
10 × 10 × 2 ÷ 324 = **0.62 cubic yards** (16.7 cu ft)
**Area-only mode:** If you know total square footage (lawn renovation, community plot), multiply area (sq ft) × depth (in) ÷ 12 for cubic feet, then ÷ 27 for yards.
**Coverage shortcut:** At 2 in depth, **1 cubic yard covers ~162 sq ft**. At 1 in refresh, one yard covers ~324 sq ft. At 3 in till-in, ~108 sq ft.
**Metric formula:**
Volume (m³) = Area (m²) × Depth (cm) ÷ 100
**Example — 20 m² at 5 cm:**
20 × 0.05 = **1.0 m³** (1,000 liters)
Finished compost is sold **bulk by the cubic yard** or in **bagged cubic feet** (1.0–1.5 cu ft is common). Add **5–15% extra** for settling, wheelbarrow spillage, and uneven spreading — compost is fluffier than topsoil and compresses after rain.
The calculator treats the amended zone as a flat rectangular prism (or known area × depth). An optional buffer increases the order quantity for settling and spillage.
Formula
cu yd = L(ft) × W(ft) × D(in) ÷ 324 | cu ft = area(sq ft) × D(in) ÷ 12 | m³ = area(m²) × D(cm) ÷ 100Tap Top-dress, Bed amend, Till into soil, or Lawn top-dress — each sets a recommended depth and shows guidance. Use Quick presets for common bed and lawn sizes.
Rectangle mode for beds; total area for lawns or irregular plots. Measure only the zone receiving compost, not paths or patios.
Depth presets (1 in refresh, 2 in amend, 3 in till-in) sit on the main form. Bulk suppliers quote finished compost by the cubic yard — round up for delivery minimums.
Enter your bag size on the main form (1.5 cu ft is common). Results show bag count, estimated bulk weight, and a bulk vs bag recommendation.
If your compost is part of a soil mix, the blend table shows total fill for 30–50% compost recipes. For full raised-bed fill, open Raised Bed or Garden Soil Calculator.
Enable the buffer on the main form for first-time amendments or fluffy bulk compost. Ten percent is the default; light refresh layers may need none.
Input
10 ft × 10 ft × 2 inOutput
16.7 cu ft · 0.62 cu yd · 12 bags at 1.5 cu ft10 × 10 × 2 ÷ 324 = 0.62 cu yd. Bags: ceil(16.7 ÷ 1.5) = 12.
Input
8 ft × 4 ft × 3 inOutput
8 cu ft · 0.30 cu yd32 sq ft × 3 in ÷ 12 = 8 cu ft — a partial yard; bags or shared delivery with neighbors.
Input
200 sq ft × 2 inOutput
33.3 cu ft · 1.23 cu yd200 × 2 ÷ 12 = 33.3 cu ft. ÷ 27 = 1.23 yards — bulk delivery break-even zone.
Input
20 m² × 5 cmOutput
1.0 m³ · 1,000 L20 × 0.05 m depth = 1.0 cubic meter of finished compost.
Common real-world scenarios where this tool saves time.
A 10×10 ft bed at 2 in depth needs ~0.62 cu yd (16.7 cu ft). Ordering 0.75–1 yard with a 10% buffer covers spillage. At 1.5 cu ft per bag, plan for 12–13 bags.
4×8 ft bed at 3 in compost tilled in: 8 × 4 × 3 ÷ 324 = 0.30 cu yd. Blend on a tarp with native soil before filling — use Garden Soil Calculator for total fill if building from scratch.
500 sq ft lawn at 1 in compost: 500 × 1 ÷ 12 = 41.7 cu ft → ~1.54 cu yd. Thin layers (¼–½ in) are safer for turf; 1 in is aggressive renovation territory.
EU gardeners enter m² and cm for direct m³ and liter readouts — useful when municipal compost is sold in bulk bags labeled in litres.
Step-by-step chains that connect related tools for common tasks.
From soil test to delivery in four steps.
Square feet one loose cubic yard of compost covers at even depth.
| Depth | Sq ft per cu yd | Typical use |
|---|---|---|
| 1 in | 324 | Lawn top-dress · light refresh |
| 2 in | 162 | Standard bed amendment |
| 3 in | 108 | Till-in · heavy organic boost |
| 4 in | 81 | Renovation — usually mixed, not surface-only |
Formula: 324 ÷ depth (inches) = sq ft per cubic yard.
Approximate coverage per bag and bags needed per cubic yard.
| Bag size | Covers (sq ft) | Bags per cu yd |
|---|---|---|
| 1 cu ft | 6 | 27 |
| 1.5 cu ft | 9 | 18 |
| 2 cu ft | 12 | 14 |
| 3 cu ft | 18 | 9 |
Coverage = bag cu ft ÷ (depth in ÷ 12). Round bag orders up.
| Depth | Imperial | Metric equivalent | Best for |
|---|---|---|---|
| Light refresh | ½–1 in | 1–2.5 cm | Established beds · lawn dressing |
| Standard amend | 2 in | 5 cm | Vegetable beds · default preset |
| Till-in layer | 2–3 in | 5–8 cm | New beds mixed into native soil |
| Too deep (avoid) | 4+ in unmixed | 10+ cm | Root zone saturation risk |
Choose format based on volume, access, and quality needs.
| Volume needed | Best format | Trade-off |
|---|---|---|
| Under 0.5 cu yd | Bagged retail | Higher $/cu ft, no delivery minimum |
| 0.5–2 cu yd | Compare bulk vs pallet | Delivery fee vs bag sale + your labor |
| 2+ cu yd | Bulk truck delivery | Lowest $/cu yd; needs driveway or tarp drop |
Municipal compost is often the best value above 1 yard if quality is acceptable.
Hot or unfinished compost can burn roots. Use only **finished**, earthy-smelling compost for 2–3 in layers. Let fresh piles cure before spreading.
One cubic yard equals **27 cubic feet**. A 16.7 cu ft order is under one yard, not 16 yards.
For new beds, till compost into the top 6–8 in of native soil. Surface-only layers dry out quickly on clay.
Measure only the **planted or turf area** receiving compost, not walkways and patios.
Bulk compost is loose-loaded. Add 10% for settling after the first rain and wheelbarrow loss.
Amendment layers are 1–3 in. For 12 in full bed fill, use Raised Bed Soil or Garden Soil Calculator instead.
The calculator handles conversion. Manual: divide depth in inches by 12 before multiplying by area in sq ft.
Suppliers may quote tons, but garden math is by **volume**. Moist compost weighs more per yard than dry — always confirm cubic yards.
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At 2 in depth (default), 10×10 ft = 100 sq ft. Volume = 100 × 2 ÷ 12 = 16.7 cu ft, or about 0.62 cubic yards. Round up to 1 yard for bulk or 12 bags at 1.5 cu ft each.
One cubic yard = 27 cu ft. Divide 27 by bag size: ~18 bags at 1.5 cu ft, ~14 at 2 cu ft, ~27 at 1 cu ft. Always round up.
2 inches (5 cm) is the standard annual amendment. Till it into the top 6–8 inches of soil in spring or fall. A 1-inch top-dress is enough for maintenance beds with good organic matter.
For compost amendments: cubic yards = bed length (ft) × width (ft) × spread depth (in) ÷ 324. Total-area mode: (sq ft × depth in ÷ 12) ÷ 27. Use 1–3 in for top-dress, not 12 in fill.
Pure compost alone drains too fast and shrinks. Blend 30–50% compost with topsoil and aeration. Calculate total fill with Garden Soil Calculator, then split by your recipe.
Divide 324 by depth in inches. At 2 in, one yard covers 162 sq ft. At 1 in, 324 sq ft. At 3 in, 108 sq ft.
Under ~0.5 cubic yard, bags are simpler. Above 1–2 cubic yards, bulk delivery usually costs less per cubic foot if you can receive a dump and spread within a few days.
Yes — finished compost can settle 10–15% after rain and watering. Enable the buffer for first orders; light refresh layers may need none.
Select Till into soil (3 in) in the calculator. For a 10×10 ft bed, 3 in = 25 cu ft (~0.93 cu yd). Till into the top 6–8 in of native soil — do not pile 4+ in unmixed on the surface.
Use Lawn top-dress (1 in) and enter total lawn sq ft. 500 sq ft at 1 in = ~41.7 cu ft (1.54 cu yd). For maintenance, ¼–½ in is safer than 1 in on turf.
A 4×8 ft surface at 2 in depth = 32 × 2 ÷ 12 = 5.3 cu ft — about 0.2 cu yd. Four bags at 1.5 cu ft covers it. For 12 in fill inside the frame, use Raised Bed Soil Calculator.
Volume math is identical, but municipal bulk compost may be coarser and wetter — it compacts more. Order 10% extra compared to dry bagged product.
Compost bed measurements and amendment depth values never leave your device — EverydayTools performs all volume math locally without sending garden dimensions to our servers.
Volume estimates only — not agronomic consulting, nutrient management, or commercial quantity surveying. Confirm order quantities and compost quality with your supplier.
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Reviewed on 2026-06-27.
What are you doing?
2 in — standard vegetable bed spring amendment (default).
Compost depth presets
Use case chips set depth — 1 in refresh, 2 in amend, 3 in till-in. Deeper than 4 in unmixed can saturate roots.
Bagged compost — often 1.0–1.5 cu ft. Leave blank to skip bag count.
1 cubic yard covers
| Depth | Sq ft |
|---|---|
| 1 in | 324 |
| 2 in | 162 |
| 3 in | 108 |
| 4 in | 81 |
Bag coverage at 2 in depth
| Bag | Covers | Per cu yd |
|---|---|---|
| 1 cu ft bag | 6 sq ft | 27 bags |
| 1.5 cu ft (40 L) | 9 sq ft | 18 bags |
| 2 cu ft bag | 12 sq ft | 14 bags |
| 3 cu ft bag | 18 sq ft | 9 bags |