Garden Soil Calculator

Estimate how much soil, topsoil, compost, mulch, or raised bed mix you need for a garden bed, planter, lawn area, or landscaping project. Calculate cubic feet, cubic yards, bag count, material cost, and optional compost mix.

Calculate Garden Soil

Soil Volume = Length × Width × Depth. Convert inches to feet before calculating volume.
Your result will appear here.

How the garden soil calculator works

Rectangular mode:
The calculator multiplies length, width, and soil depth to estimate the amount of soil needed for a rectangular garden bed.

Round mode:
The calculator uses the bed diameter to estimate the circular area, then multiplies by soil depth.

Raised bed mode:
The calculator estimates soil volume for raised beds and adds extra material for settling or waste.

Top dressing mode:
The calculator works for shallow soil, compost, or mulch layers spread over an existing garden or lawn area.

Why use a garden soil calculator?

A garden soil calculator helps estimate how much soil, compost, topsoil, mulch, or raised bed mix to buy before starting a garden project.

It can help prevent buying too little material, overpaying for extra bags, or underestimating the amount needed for raised beds, planters, flower beds, and vegetable gardens.

What your result means

Your result shows estimated soil volume in cubic feet and cubic yards, the number of bags needed, the estimated bagged soil cost, the estimated bulk soil cost, garden bed area, soil depth, extra material allowance, and optional compost-to-soil mix amounts.

Garden soil formulas

Frequently asked questions

How do I calculate soil for a garden bed?

Multiply the garden bed length by the width, then multiply by the soil depth in feet. If the depth is in inches, divide it by 12 first.

How many cubic feet are in one cubic yard of soil?

One cubic yard equals 27 cubic feet. Bulk soil is usually sold by the cubic yard, while bagged soil is often sold by cubic feet or quarts.

How deep should soil be in a raised garden bed?

Many raised beds use 8 to 12 inches of soil, but deeper beds may be useful for larger root vegetables, shrubs, or deep-rooted plants.

Should I add extra soil when calculating?

Yes. Adding 5% to 15% extra can help account for settling, uneven ground, compaction, and small measuring differences.

Is this garden soil calculator exact?

No. This is an estimate. Actual soil needs can vary based on bed shape, soil settling, compaction, moisture, slope, and how full you want the bed.