Soil Calculator
Where the topsoil calculator is tuned to growing layers, this soil calculator is the general-purpose tool: any outdoor area where material is sold by volume or weight. Give it one or more shapes, the depth the material needs to sit at, and an optional supplier density, and it works out area, cubic feet, cubic yards, an estimated tonnage and bag counts, then rounds the order volume up for purchasing. It handles garden soil mixes, screened fill, planting substrate and ordinary earth replacement equally well, because the engine only needs geometry, depth and density. A waste allowance is applied before the recommended order quantity, and a price field turns the volume into a material cost if you already have quotes. It is aimed at anyone who knows the material they are buying but not how much of it the space will take — from a weekend gardener filling a bed to a landscaper pricing bulk fill.
Calculator input
Project areas
Use one or more areas. The engine adds them before calculating volume.
What this calculator calculates
- Combined area in square feet across every shape entered
- Volume in cubic feet and cubic yards at the entered depth
- Estimated tons using the default density or your supplier figure
- Order quantity rounded up after the waste allowance is applied
- Bag counts for common bag sizes of this material
- Material cost from the unit price you enter
Projects this calculator covers
- Garden and planting bedsReplacing or topping up the soil layer where plants will actually grow.
- Bulk fill and low spotsBringing ground level up or filling excavations with screened or ordinary fill material.
- Planters and large containersVolume by inside dimensions, with extra allowance because containers settle quickly.
- Landscaping rebuildsReinstating soil after works, when the depth to add varies from area to area.
How the calculation works
Enter one or more shapes, the material depth and an optional supplier density. The engine converts the total volume into common purchase units.
Formula: Area × depth ÷ 12 = cubic feet; divide by 27 for cubic yards; multiply by density for an estimated tonnage.
Worked example
15 × 24 ft soil area at 4 in depth
Use supplier-specific density when available.
Reading the results
- Density changes the weight, not the volume. Cubic yards come from geometry alone. Tons come from density, so garden mix, damp fill and dry screened soil can give three different weights for the same yard count.
- Soil is not the same as topsoil. The general engine does not assume a growing layer. If the job is specifically a lawn or bed amendment, the topsoil page carries the depth guidance for that use.
- Calculated versus ordered volume. The order quantity includes waste and is rounded up to a quarter cubic yard, which is the number to take to a supplier rather than the exact calculated figure.
- Bags or bulk. Small volumes are easier as bags; larger ones are cheaper by the yard or load. The purchase advice line shows which side of that line your result falls on.
Assumptions
Central engine assumptions can be inspected in the methodology view. User-entered prices never get replaced with invented market prices.
Practical planning guidance
- Start from the material name on the supplier invoice and match the density to it rather than to a generic soil value.
- Measure every area separately when the fill depth changes; a single average depth hides the areas that need more.
- Keep a waste allowance for excavation edges and uneven subgrades, which rarely accept a clean uniform depth.
- Order by volume when you can, because weight-based pricing moves with moisture and you cannot see that in advance.
- Check whether the material is sold screened or unscreened — the volume is the same, the placement effort is not.
Common mistakes
- Assuming topsoil and fill dirt share the same density and then receiving a heavier load than planned.
- Ordering by weight without confirming what the supplier actually sells by.
- Using a planter depth for ground fill, or the reverse, because both are just "soil" on the invoice.
- Leaving the density at the default when a specific product figure was available.
- Forgetting the waste allowance on areas with irregular edges or soft ground that takes extra material.
Important limitations
Frequently asked questions
Can this calculate fill dirt as well as garden soil?
Yes. The engine only needs area, depth and density, so fill works the same way. Enter a supplier density when you have one, because fill is often heavier than screened garden soil.
What density should I use for soil?
The default is a planning value. If the supplier publishes a tons-per-cubic-yard figure for the actual product, enter it in the density field and the weight estimate follows it.
How do I convert cubic yards of soil to tons?
Multiply the cubic yards by the density in tons per cubic yard. The result panel does this for you and shows which density it used.
Is this the right calculator for a raised bed?
It will give you the volume, but the topsoil page carries raised-bed depth guidance and inside-dimension reminders. Use that one when the job is growing material rather than bulk fill.
How much waste should I add for soil?
The default allowance covers normal trimming and uneven ground. Increase it where the subgrade is rough or where material is lost over the edges of the area.
Can I price the soil in this calculator?
Yes, enter your price per cubic yard, ton or bag. Only the quantity you calculated gets priced, and no market rate is ever filled in for you.
Planning guides
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Enter your dimensions, then calculate. Results stay tied to the tested engine.