Fill Dirt Calculator — Cubic Feet
Calculate excavation and backfill volumes in real time with a compaction factor.
Fill Dirt vs Topsoil
Fill dirt is the dense, low-organic subsoil used for structural work — building up grade, filling pools, backfilling foundations. It compacts well and doesn't settle dramatically.
Topsoil is the upper layer rich in organics. It's biologically active and continues to decompose, so it settles over time — bad for structural fill, good for planting.
For most yard projects, place fill dirt at the bottom and finish with 4–6 inches of topsoil for plant growth.
Compaction Explained
Loose dirt straight from a truck has air gaps. Once compacted by foot traffic, weather, vehicle weight or mechanical tamping, the volume reduces 10–20%. To end up with 100 ft³ compacted, order ~115 ft³ loose.
Mechanical compaction (plate compactor or jumping jack) every 6–8 inches of lift is required for any structural application — driveways, building pads, foundations.
Excavation vs Fill
If you're excavating, the displaced dirt expands 10–25% when removed (called the "swell factor"). 100 ft³ in the ground becomes ~120 ft³ in a dump truck. Plan haul-off accordingly.
If you're filling, the opposite happens — loose loads compress under their own weight and finish settling. Use the calculator's compaction factor for an accurate order.
Pricing Guide
Clean fill dirt: $5–$15 per cubic yard. Screened topsoil: $20–$50 per cubic yard. Delivery: $50–$150 depending on distance. Many homeowners can source free clean fill from local excavation jobs.
Weight and Finishing the Job
A cubic yard of fill dirt weighs roughly 2,200–2,800 lbs — check the weight calculator before scheduling delivery if you're not sure your driveway or the delivery truck's access can handle a load that heavy. Once fill dirt is graded and compacted, most projects finish with 4–6 inches of topsoil for planting — use the soil calculator to size that top layer separately, since it needs its own depth and doesn't get the fill dirt's 1.15 compaction multiplier.
Frequently Asked Questions
What is fill dirt?
Subsoil used for filling holes, raising grade or building up areas. Unlike topsoil, it contains few organics — ideal for structural fill.
How much fill dirt do I need?
Multiply length × width × depth in feet for cubic feet, then add 15% for compaction.
What's a compaction factor?
Loose fill compresses 10–20% under load. Order 15% extra (multiply by 1.15) to end up with the right volume after compaction.
How heavy is a cubic yard of fill dirt?
About 2,200–2,800 pounds depending on moisture and clay content.
What's the difference between fill dirt and topsoil?
Fill dirt is subsoil for structural use; topsoil is the upper organic layer for growing plants. Don't use topsoil as structural fill — it settles.
How much does fill dirt cost?
$5–$15 per cubic yard for clean fill; delivery adds $50–$150 depending on distance.
Can I use fill dirt for a backyard?
Yes for grading and raising areas. Top with 4–6 inches of topsoil before seeding or sodding.
How do I calculate excavation volume?
Length × width × depth of the hole in feet. Add 10% if sides will be sloped, since the top opening is larger than the bottom.