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Soil Calculator

Calculate how much soil you need for raised beds, planters, and gardens โ€” get volume in cubic feet, liters, and bags

Bag Size
Quick add common sizes
Pro tip
For beds deeper than 12" (30 cm), save money with the Hรผgelkultur method: fill the bottom 1/3 with logs, branches, cardboard, and leaves. Then add soil on top. This reduces soil needed by 30-40% and improves drainage.

About This Tool

Planning a raised bed or filling planters? This calculator tells you exactly how much soil to buy. Enter the dimensions of your bed or container, and get the volume in cubic feet, cubic yards, liters, and gallons โ€” plus the number of bags you need based on common bag sizes. Supports multiple beds of different sizes, so you can plan your entire garden at once. Choose between rectangular beds, circular pots, and tapered containers. Accounts for the "fluff factor" in bagged soil and shows both volume needed and recommended overage. Works in metric (cm, liters) or imperial (inches/feet, cubic feet). Never buy too little โ€” or too much โ€” soil again.

How to Use

1. Enter bed dimensions: length, width, and depth 2. For round pots, enter diameter and depth 3. Add more beds/containers as needed 4. Select your bag size (or enter custom) 5. See total volume and bags needed 6. Add 10-15% extra for settling

Frequently Asked Questions

How do I calculate soil for a raised bed?
Multiply length ร— width ร— depth. For a 4ft ร— 8ft bed that's 12 inches deep: 4 ร— 8 ร— 1 = 32 cubic feet. Convert to cubic yards by dividing by 27 (about 1.2 cubic yards). This calculator does the math and converts to bags automatically.
How many bags of soil do I need for a 4x8 raised bed?
A 4ร—8 foot bed that's 12 inches deep needs about 32 cubic feet of soil. A typical large bag (2 cu ft) means you need 16 bags. For 10-inch depth, it's about 27 cu ft or 13-14 bags. Use this calculator for exact amounts.
Should I fill my entire raised bed with potting soil?
No โ€” it's expensive and unnecessary. For beds deeper than 12 inches, use the 'Hรผgelkultur' method: fill the bottom third with logs, branches, and leaves, then add soil on top. This saves money, improves drainage, and feeds plants as it decomposes.
What's the difference between potting soil, garden soil, and topsoil?
Potting soil is lightweight, sterile, and best for containers. Garden soil is heavier, meant for in-ground beds. Topsoil is the cheapest but lowest quality โ€” good for filling but not planting. For raised beds, use a mix: 60% topsoil, 30% compost, 10% potting soil.
How much does soil settle after filling?
Bagged soil settles 10-20% over the first few weeks as it compacts and moisture distributes. Buy 10-15% extra to top off after settling. This calculator shows both exact volume and recommended overage.
How do I calculate soil for a round pot?
Use the formula: ฯ€ ร— radiusยฒ ร— depth. For a 12-inch diameter pot that's 10 inches deep: 3.14 ร— 6ยฒ ร— 10 = 1,130 cubic inches, or about 0.65 cubic feet (18 liters). This calculator handles round containers automatically.

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