Fill Dirt Calculator
Calculate fill dirt for grading and backfill. Enter values for instant results with step-by-step formulas.
Formula
Loose Volume = Compacted × (1 + Compaction %)
Calculate compacted volume needed, then add compaction factor to determine loose volume to order. Soil shrinks when compacted.
Worked Examples
Example 1: Backfill Foundation
Problem:Foundation perimeter 80 ft long, 4 ft wide trench, needs 2 ft of fill after foundation is set.
Solution:Area: 80 × 4 = 320 sq ft\nDepth: 2 ft\n\nCompacted volume:\n320 × 2 = 640 cu ft\n640 ÷ 27 = 23.7 yards\n\nLoose (20% compaction):\n23.7 × 1.20 = 28.4 yards\n\nOrder: 29-30 cubic yards
Result:Order 30 cubic yards fill dirt
Example 2: Level Yard
Problem:Low area 30×40 ft needs 8\" fill to level with rest of yard.
Solution:Area: 30 × 40 = 1,200 sq ft\nDepth: 8\" = 0.667 ft\n\nCompacted: 1,200 × 0.667 = 800 cu ft\n800 ÷ 27 = 29.6 yards\n\nLoose (25%):\n29.6 × 1.25 = 37 yards\n\nTrucks: 4 loads
Result:37 yards (4 truckloads)
Example 3: Driveway Base
Problem:Driveway 50×12 ft needs 4\" compacted stone base.
Solution:Area: 50 × 12 = 600 sq ft\nDepth: 4\" = 0.333 ft\n\nCompacted: 200 cu ft = 7.4 yards\n\nLoose (15% for crushed stone):\n7.4 × 1.15 = 8.5 yards\n\nOrder: 9 cubic yards
Result:Order 9 yards crushed stone
Frequently Asked Questions
What is fill dirt?
Fill dirt is subsoil (no organic matter) used to raise ground level or fill holes. Different from topsoil (has organic matter for plants). Fill dirt compacts well and doesn't decompose. Common uses: foundation backfill, grading, raising low areas.
How does compaction affect fill quantity?
Fill dirt compacts 15-30% after placement and compaction. Order loose volume = compacted volume × (1 + compaction %). Example: need 10 compacted yards, with 20% compaction = 12 loose yards to order. Otherwise you'll be short after compacting.
Clean fill vs regular fill dirt?
Clean fill: free of debris, organic matter, contaminants. Passes through screen, suitable for building sites. Regular fill: may contain rocks, roots, some debris. Cheaper but may not meet code for structural backfill. Use clean fill near foundations.
How much does fill dirt cost?
Bulk fill dirt: $10-50 per cubic yard depending on quality and location. Delivery: $50-150. Topsoil costs more ($20-80/yard). Free fill sometimes available from excavation sites - you pay delivery/loading. Small bags at stores are very expensive per volume.