Excavation Calculator
Use our free excavation calculator to determine exactly how much soil you'll dig up and how much space it will occupy. Designed for contractors, excavator operators, and site estimators, this tool calculates bank volume (in-place soil), loose volume (after excavation), and compacted volume (after compaction) using standard swell and shrink factors for eight soil types.
How to use this calculator.
- Select your unit system. Choose imperial (feet, inches) or metric (meters, centimeters) using the toggle above.
- Enter your excavation dimensions. Input the length, width, and depth of the area to be excavated. For trenches, enter the trench length, average width, and depth.
- Select your soil type. Choose from eight common soil classifications. The soil type determines swell and shrink factors: clay swells much more than sand when excavated.
- Review your three volumes. The calculator shows bank volume (what's in the ground), loose volume (what fills your truck), and compacted volume (what you get after compaction).
- Use the loose volume for trucking. Always order dump trucks based on loose cubic yards, not bank cubic yards.
How do you calculate excavation volume and soil calculations?
Excavation quantities are calculated in three states: bank (undisturbed), loose (after digging), and compacted (after compaction).
Bank Volume (cu yd) = Length (ft) × Width (ft) × Depth (in) ÷ 324
Loose Volume (cu yd) = Bank Volume × Swell Factor
Compacted Volume (cu yd) = Bank Volume × Shrink Factor
Where:
- Bank Cubic Yards (BCY) is the volume of soil in its natural, undisturbed state.
- Loose Cubic Yards (LCY) is the volume after excavation: soil expands (swells) when dug up.
- Compacted Cubic Yards (CCY) is the volume after mechanical compaction: soil shrinks below bank volume.
- Swell Factor is always ≥ 1.0 (soil expands when excavated). Clay can swell 50%.
- Shrink Factor is typically < 1.0 (compacted soil occupies less volume than bank soil).
Example calculation.
Let's calculate the excavation for a foundation.
Scenario: You're excavating for a basement foundation that is 30 ft long, 20 ft wide, and 4 ft (48 inches) deep in clay soil.
- Calculate bank volume: 30 ft × 20 ft × 48 in ÷ 324 = 88.89 cu yd (BCY)
- Apply swell factor (clay, CL = 1.30): 88.89 × 1.30 = 115.56 cu yd (LCY)
- Apply shrink factor (clay, CL = 0.85): 88.89 × 0.85 = 75.56 cu yd (CCY)
Result: You're excavating approximately 89 bank cubic yardsof clay. This will fill about 116 loose cubic yards in dump trucks (about 8 tandem-axle loads at 15 yd³ each). If you need to re-compact this soil as fill elsewhere, you'll get about 76 compacted cubic yards.
Tips from the field.
- Always calculate trucking from loose volume, not bank. A 15-yard dump truck holds 15 loose cubic yards. If you order based on bank volume, you will be short by the swell percentage (15-50% depending on soil).
- Swell varies with moisture. Wet clay swells more than dry clay. Sandy soils swell less but can flow when saturated. Adjust factors based on observed site conditions.
- Rock swells dramatically. Blasted rock can swell 50-80%. A 100-yard rock cut will produce 150-180 loose truckloads. Always separate rock quantities from soil in your takeoff.
- Compaction requires moisture control. Soil must be within 2% of optimum moisture content (from a Proctor test) to achieve specified compaction. Too dry or too wet = failed compaction test.
- OSHA requires trench protection at 5+ feet. Any trench deeper than 5 feet requires sloping, benching, shoring, or a trench box unless in stable rock. Excavation safety is not optional.
Disclaimer: This calculator provides estimates for planning purposes only. Actual soil behavior varies significantly with moisture content, density, and site-specific conditions. For structural excavations, retaining walls, or deep trenches, consult a licensed geotechnical engineer. PavementCalculator.com assumes no liability for excavation planning errors or safety incidents.
Cost, price, and density figures on this page reflect approximate U.S. averages as of August 2026 and vary by region, supplier, and material availability.
Frequently asked questions.
How do I calculate excavation volume?
Multiply the excavation area (length × width) by the depth, then divide by 27 to convert cubic feet to cubic yards. For example, a 30 ft × 20 ft × 4 ft deep excavation = 2,400 cu ft ÷ 27 = 88.9 cubic yards. Use our calculator above for your exact dimensions, including soil swell factors.
How much does excavation cost?
Excavation costs $50 to $200 per cubic yard depending on soil type, access difficulty, and depth. Simple topsoil removal costs $50-$75/yd³, while deep foundation excavation in rocky soil can cost $150-$200/yd³. Most residential projects cost $1,500-$5,000 total.
What is soil swell factor?
Soil swell factor is the percentage increase in volume when soil is excavated from its natural (bank) state to a loose state. Clay swells 30-45%, silt swells 25-35%, sand swells 10-20%, and blasted rock can swell up to 60%. You must account for swell when planning truck hauling capacity.
How deep can I excavate without shoring?
Per OSHA regulations, trenches 5 feet or deeper require protective systems (shoring, shielding, or sloping). Excavations less than 5 feet deep may not need shoring if a competent person determines there's no potential for cave-in. Always check local codes and soil classification before digging.
How many cubic yards can a dump truck hold?
A standard dump truck holds 10-16 cubic yards of loose soil. A tri-axle dump truck carries 15-22 cubic yards. To calculate truckloads needed, divide your loose (swelled) excavation volume by the truck capacity. For 88.9 bank cubic yards of clay (1.30 swell = 115.6 loose yd³), you'd need 8-12 truckloads.
What is the difference between bank, loose, and compacted cubic yards?
Bank cubic yards (BCY) is soil in its natural, undisturbed state. Loose cubic yards (LCY) is soil after excavation: it has expanded (swelled) by 15-50%. Compacted cubic yards (CCY) is soil after mechanical compaction: it typically occupies 5-30% less volume than bank soil. Always use the correct measure: BCY for estimating, LCY for trucking, CCY for fill requirements.
How much does excavation cost per cubic yard?
As of 2026, excavation costs $50-$200 per cubic yard depending on depth, soil type, access, and location. Simple topsoil removal is $50-$80/yard. Deep basement excavation with rock is $150-$200+/yard. Hauling and disposal are separate costs: budget $20-$60 per ton for disposal depending on material type and local tipping fees.
How many cubic yards does a dump truck hold?
A standard tandem-axle dump truck holds 10-16 loose cubic yards. A tri-axle holds 16-22 yards. A semi-trailer end dump holds 20-30 yards. Divide your loose cubic yards by the truck capacity to estimate the number of loads.