NOVORY

Soil Calculator

Calculate how much soil you need for garden beds, raised beds, or landscaping areas.

Quick answer

22 bags of 1.5 ft³, or about 1.5 cubic yards in bulk.

Calculator

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How it works

Length × Width × Depth = Volume

For imperial inputs, length and width are in feet and depth is in inches. The calculator converts inches to feet automatically, then multiplies the three dimensions to get cubic feet.

Cubic feet ÷ 27 = Cubic yards

Since one cubic yard equals 27 cubic feet (3 ft × 3 ft × 3 ft), dividing by 27 converts the volume to cubic yards — the standard unit for ordering bulk soil.

The recommended order amount includes your selected waste factor so you have a buffer for settling and uneven ground.

Worked example

A 10 ft × 5 ft garden bed at 6 inches deep:

10 × 5 × (6/12) = 25 ft³

25 ÷ 27 = 0.93 yd³

0.93 × 1.10 = 1.02 yd³ (with 10% waste)

Order approximately 1.02 cubic yards of soil.

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Soil is the only material on this site that shrinks after you buy it. Freshly delivered soil settles 10–20% in the first season, which is why a raised bed filled 'to the top' in April sits half-empty by July. Estimate honestly, then order like a pessimist.

This calculator turns bed dimensions into cubic yards — the unit bulk suppliers sell — with a waste factor for settling. Around one cubic yard is the breakpoint: below it, bags are convenient; above it, bulk delivery is far cheaper.

How to measure soil beds

  1. Measure the inside of the bed — the soil area, not the outside of the boards. A 4×8 bed built from 2× lumber is really about 3.7 × 7.7 ft of soil.
  2. Enter depth in inches: 12 for most raised beds, 6–8 for top-dressing a lawn.
  3. Choose bags or bulk before you shop: a cubic yard is 27 cubic feet, and bag math gets expensive fast past that.
  4. If the bed is new, the 10% default covers settling. For a bed you're topping up after a season, 5% is plenty.

Bagged soil: what a cubic yard means in bags

Bag sizeBags per cubic yardCovers at 3 in deep
1 ft³274 sq ft
1.5 ft³186 sq ft
2 ft³13.58 sq ft

Coverage = bag volume ÷ depth. Bulk 'garden mix' varies; ask what the blend is before you buy.

Worked example: soil for a 4×8 raised bed

A 4 ft × 8 ft bed, 12 inches deep, filled with 1.5-ft³ bags:

  1. Volume: 4 × 8 × (12 ÷ 12) = 32 ft³.
  2. To cubic yards: 32 ÷ 27 = 1.19 yd³.
  3. In bags: 32 ÷ 1.5 = 21.3 → 22 bags.
  4. Bulk order: round to 1.25–1.5 yd³ to cover settling.

22 bags of 1.5 ft³, or about 1.5 cubic yards in bulk.

Pro tips for buying soil

  • Never fill a vegetable bed with 100% topsoil — it compacts into concrete. A 60/30/10 mix of topsoil, compost, and aeration (perlite or rice hulls) stays workable.
  • Order bulk only if the truck can reach the spot. A 'driveway delivery' 50 feet from the bed means 50 feet of wheelbarrow.
  • Water the bed thoroughly after filling and top it up before planting — most settling happens in the first two soakings.
  • For lawn top-dressing, ¼–½ inch is plenty. More than that smothers the grass you're trying to help.

How to use the soil calculator

1. Choose your unit system — Imperial (feet and inches) or Metric (meters and centimeters).

2. Enter the length and width of the area you want to fill with soil.

3. Enter the desired depth — 6 inches is typical for garden beds.

4. Select a waste factor — 10% is recommended to account for settling.

5. Click Calculate to see your results in cubic yards, cubic feet, and cubic meters.

How soil volume is calculated

Soil volume is calculated by multiplying the three dimensions of the area: length, width, and depth. This gives the total volume of space the soil will fill.

In the imperial system, the result is in cubic feet. Since bulk soil is often sold by the cubic yard, the calculator divides by 27 to convert. In the metric system, the result is directly in cubic meters.

The waste factor is applied as a percentage increase to the base volume, giving you a recommended order amount that accounts for settling and uneven ground.

How much soil do I need?

The amount of soil you need depends on the size and depth of the area you are filling. A small raised bed might need less than 1 cubic yard, while a large landscaping project could require several cubic yards.

Always measure carefully and add a waste factor. Soil settles after installation, so ordering slightly more than the calculated volume ensures full coverage.

Why add a waste factor?

A waste factor accounts for soil that is lost to settling, compaction, spillage, or uneven ground. Without a buffer, you risk having thin spots in your coverage.

The standard recommendation is 10%. For deeper fills or areas with irregular shapes, 15% is safer. For simple, well-prepared areas with precise measurements, 5% may be enough.

Soil calculator example

Let's say you're filling a garden bed that is 10 feet long, 5 feet wide, and 6 inches deep.

First, convert the depth to feet: 6 inches ÷ 12 = 0.5 feet.

Then calculate the volume: 10 × 5 × 0.5 = 25 cubic feet.

Convert to cubic yards: 25 ÷ 27 = 0.93 cubic yards.

With a 10% waste factor: 0.93 × 1.10 = 1.02 cubic yards.

You should order approximately 1.02 cubic yards of soil for this project.

Frequently Asked Questions

How do I calculate how much soil I need?+
Multiply the length by the width by the depth of the area you want to fill. In imperial units, this gives cubic feet — divide by 27 for cubic yards. In metric units, the result is cubic meters. Add a waste factor to account for settling and uneven ground.
How many cubic yards of soil do I need?+
Calculate the volume in cubic feet by multiplying length × width × depth (with depth converted to feet), then divide by 27. For example, a 10 ft × 5 ft area at 6 inches deep has a base volume of approximately 0.93 cubic yards before waste.
How deep should topsoil be?+
For garden beds, 6–12 inches of topsoil is typical. For filling raised beds, 8–12 inches is common. For topping existing lawns, 1–2 inches is usually sufficient. The depth you choose depends on what you are planting and the existing soil conditions.
How many bags of soil do I need?+
Bag sizes vary — a common 1.5 cubic foot bag of soil covers about 6 square feet at 3 inches deep. To estimate the number of bags, divide the required volume in cubic feet by the volume stated on the bag packaging.
What is the difference between cubic feet and cubic yards?+
A cubic yard equals 27 cubic feet (3 ft × 3 ft × 3 ft). Bulk soil is typically ordered by the cubic yard, while bagged soil is sold by the cubic foot. The calculator provides both so you can compare bulk and bagged options.

Related Guides

How Much Soil Do I Need for a 4x8 Raised Bed?

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