Calculate bank excavation, loose spoil, bedding, pipe displacement, backfill balance, truckloads, and optional costs for rectangular or user-specified sloped trenches.
Rectangular trenches use length × width × depth. Sloped trenches use a trapezoidal cross-section multiplied by length.
Geometric excavation is bank volume. Swell converts bank soil to loose spoil without changing mass.
bank volume = length × width × depth × quantityvolume = ((bottom width + top width) ÷ 2 × depth) × length × quantitytop width = bottom width + 2 × depth × (H ÷ V)excavation − bedding − outside pipe volume − permanent volumeloose volume = bank volume × (1 + swell rate)A 100 × 2 × 4 ft rectangular trench is 800 ft³, or about 29.630 yd³ bank.
At 20% swell, 800 ft³ bank occupies 960 ft³, or about 35.556 yd³ loose.
A 2 ft bottom, 6 ft top, 4 ft deep, 100 ft long trench has a 16 ft² section and 1,600 ft³ volume.
A 100 × 2 × 0.5 ft bedding zone is 100 ft³ before its separate purchase allowance.
Bank, loose, and compacted volumes are different states and are never mixed silently.
Pipe displacement uses its external cylinder, not internal capacity.
Bedding, slope, reusable soil, and compaction assumptions must come from the project.
When volume and weight capacities are entered, the larger whole-load count governs.
Top width can be entered directly or derived from a symmetric user-entered H:V slope. The calculator does not recommend a safe slope.
Bedding is calculated first as a lower rectangular material zone. Pipe and other permanent volume are then subtracted once from the remaining geometric backfill void.
The shared Earthwork balance converts required placed backfill to bank-equivalent soil using shrinkage, then compares it with the reusable fraction of excavated bank soil.
Loose surplus drives volume hauling. In-place density preserves mass and enables weight-limited loads. Excavation, hauling, and bedding costs remain separate.
This tool does not determine safe slopes, benching, shoring, trench boxes, utility clearance, soil class, groundwater control, structural design, or code compliance.
Multiply length, width, and depth for vertical sides, or multiply trapezoidal cross-sectional area by length.
The calculator converts the full-precision bank volume to cubic yards.
Enter bottom and top widths or a symmetric H:V slope supplied by the project design.
Bottom width is at trench grade; top width includes horizontal widening from sloped sides.
Swell increases loose volume after excavation but does not increase soil mass.
Multiply explicit bedding width, depth, and applicable trench length, then add a separate bedding allowance.
Subtract the pipe's outside displacement when it occupies the calculated backfill void.
Subtract bedding, pipe, and other permanent material from excavation, then apply any explicit soil-state conversion.
Divide loose export by truck volume capacity and/or export mass by weight capacity, then round up.
Yes. Included sections are calculated independently and summed before project conversions.
No. The entered slope is geometry only.
No. It does not assess shoring, shielding, benching, or trench boxes.
No. Consult qualified professionals and applicable safety and excavation requirements.