Excavation and Trench Volume Calculator
Estimate bank and loose excavation volume, weight, truckloads, and editable hauling cost for rectangular or trapezoidal cuts.
How to use the excavation calculator
- Measure the actual project. Break irregular work into separate sections and record finished dimensions consistently.
- Enter the core measurements. The quick view focuses on project geometry; add or subtract sections where the calculator supports multiple areas.
- Review purchasing assumptions. Open Advanced inputs to replace example prices, waste, coverage, density, pack size, minimum order, or delivery assumptions with current project information.
- Calculate and verify. Review the formula, limitations, whole-unit rounding, product instructions, and supplier requirements before purchasing.
Key inputs covered: Excavation profile, Excavation length, Bottom width, Top width, Depth, Identical cuts, Swell allowance, Bank density, Loose truck capacity, Excavation example price, and additional project-specific assumptions.
Result coverage: The excavation calculator reports 6 separate quantities so the primary estimate and its supporting purchase or planning values can be checked together.
How the estimate works
Cross-section area × length × quantity produces bank volume; swell increases loose haul volume while bank density estimates weight.
A trapezoid uses the average of bottom and top widths multiplied by depth and length.
Assumptions, rounding, and limitations
Dimensions are treated as finished measurements. Only deductions and allowances entered above are included. Decimal measurements display to two places; purchase quantities round up when a whole container or piece is required.
- This calculator never designs sloping, benching, shoring, shielding, access, spoil placement, or utility protection.
- OSHA requires a competent person and protective measures based on depth, soil, water, loads, and changing conditions.
- Locate utilities and obtain required permits before excavation; use measured truck payload and disposal rules.
Sources and review
These references support unit conversions and selected planning assumptions. Product instructions and local requirements control the actual project.
Last reviewed: 2026-10-09
Editorial process
BuildPlanCalc publishes the formula, editable assumptions, limitations, and supporting references so the estimate can be checked rather than treated as a black box. See the calculation and review methodology, or report a correction.
Frequently asked questions
Are the results exact?
No. Results are planning estimates based on the dimensions and assumptions entered. Confirm product coverage, site conditions, and ordering rules with the supplier.