Fill dirt calculator: cubic yards, tons and truck loads

What is the difference between fill dirt and topsoil?

They are different products for different jobs, and ordering the wrong one wastes a delivery.

Fill dirt is subsoil with the organic matter screened out. Because there is nothing in it to decompose, it does not settle further once compacted, which is exactly what you want underneath a patio, behind a retaining wall or filling a hole. Nothing grows well in it.

Topsoil is the living upper layer, full of organic matter. It grows things, and it keeps settling as that organic matter breaks down. Using it as structural fill means the surface above it sinks over the following year.

The usual pattern for a raised area is fill dirt for the bulk and depth, then four to six inches of topsoil on top for anything you want to plant.

Why fill dirt needs a compaction allowance

Because it is placed in layers and rolled, and it occupies noticeably less space compacted than it did loose in the truck. Around 20 to 25% is the usual allowance for clay-based fill.

It should go down in lifts of six to eight inches, each compacted before the next. Dumping two feet at once and rolling the top gives you a firm crust over loose material, which fails later under load. This is the single most common fill mistake.

Spec Compaction behaviour follows FHWA Earthwork Design guidance, which gives shrinkage of 10 to 25% for moderate soils and 20 to 40% for light or swampy material, with a stated tolerance of plus or minus a third. Checked August 2026. Convention The six to eight inch lift depth is standard practice rather than a published rule for residential work.

The calculator above uses 2,150 lb per cubic yard for clay-based fill dirt, 2,500 for sandy fill and 2,400 for engineered structural fill, with compaction allowances of 22%, 15% and 25% respectively. Those are mid-range figures: state your own if your supplier gives you a weight per yard.

How much does fill dirt weigh?

Material	Pounds per cubic yard	Tons per yard
Fill dirt, dry	2,000 - 2,300	1.0 - 1.15
Fill dirt, moist	2,400 - 2,700	1.2 - 1.35
Sandy fill	2,400 - 2,600	1.2 - 1.3
Clay, wet	2,800 - 3,000	1.4 - 1.5

Moisture, not composition, drives most of the variation. Wet clay is close to half again the weight of dry fill for the same volume, which matters if you are ordering by weight or working out how many loads a truck will take.

Common questions

How much fill dirt fits in a truck?

A standard tandem dump truck carries 10 to 14 cubic yards. A single-axle carries 5 to 7. Weight often limits the load before volume does, particularly with wet clay, so a truck rated for 14 yards may only be able to legally carry 10 of heavy material.

Can I use fill dirt to level a lawn?

Not on its own. Nothing grows well in it, so use it for the bulk of any significant depth change and finish with four to six inches of topsoil. For minor levelling of an existing lawn, top dressing with a soil and sand blend is the better approach.

Do I need a permit to bring in fill?

Often yes, and it catches people out. Many jurisdictions regulate fill above a certain volume or any change to drainage and grading, because water pushed onto a neighbour's land becomes a legal problem. Check before ordering rather than after.

Is free fill dirt worth taking?

Sometimes, and it is genuinely often free because contractors pay to dispose of it. The risks are that you cannot see what is mixed in, construction debris and contamination are common, and you take on the haulage. Fine for filling a hole at the back of a plot, less so under anything structural.