Structural Fill Dirt & Swell/Shrinkage Calculator

Estimate fill dirt volume with compaction factor for deep holes and site grading.

Quick Reference Coverage Chart (Mulch & Soil)

Instant pre-calculated material estimates for common US residential project sizes before compaction buffer:

Typical US Project Area Depth Volume Weight Store Bags
Deep Hole / Low Spot (15 ft × 15 ft) 225 sq ft 12 inches 10.0 cu yd 12.0 tons (24,000 lbs) Bulk Delivery Required

Engineering Formula & Material Density Constant

Compacted Fill = Geometric Volume × (1 + Compaction Shrinkage %)

Loose fill dirt hauled in by dump trucks settles significantly when compacted. A 20% compaction factor ensures you do not run short.

Compacting Fill Dirt in Lifts

Never dump 3 feet of fill dirt all at once. Compact dirt in maximum 6-inch lifts using a mechanical tamper to prevent future sinkholes.

Frequently Asked Questions

Why does fill dirt shrink after dumping?

Loose soil contains 30-50% air pockets; heavy equipment or rain compresses these voids.

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