Estimate how much material to remove from a dig site, the swell factor for hauling, and the cost to excavate. Use the Fill Calculator if you are bringing material in rather than removing it.
How this calculator works
Volume is length × width × depth, with wastage and a compaction factor stacked on top.
cubic_feet = length × width × depth × (1 + wastage%) × (1 + compaction%)cubic_yards = cubic_feet ÷ 27
- Excavated material expands ("swell") — typically +20–30% over in-place volume — so a positive compaction factor accounts for haul tonnage.
- Some authorities require a soil-management plan above a certain cubic-yard threshold; check before mobilizing.
Common questions
How much does excavated soil expand?
Most soils swell 20–30% when excavated — clay is on the higher end, sand on the lower. Use a positive compaction factor (e.g., +25%) so your haul tonnage matches the loose volume coming out of the hole.
Do I need a permit to excavate?
It depends on volume, location, and what you're digging near. Most municipalities have soil-management or fill-control bylaws above a certain cubic-yard threshold. Always call locates before any dig.
Should I include over-dig in my volume?
Yes — set the wastage allowance (typically 5–10%) to cover the over-dig that always happens at the perimeter when an excavator scoops outside the design line.
The math on an excavation takeoff is straightforward; the cost of being wrong is the calendar. Underestimate the volume and you book a second equipment day mid-job; overestimate and you’re paying haul fees on dirt you didn’t need to move. This calculator returns the bank-state volume that came out of the ground and the loose-state volume your hauler bills against, so the dispatch number and the contractor’s number agree before anyone breaks ground.
What you’ll get
Enter trench or pit length, width, and depth, then set a swell factor (the percentage soil expands when excavated and loaded onto a truck) and an optional haul cost per cubic yard. The calculator returns bank volume, loose volume after swell, truckload count at common box sizes, and an estimated haul cost.
A sample trench
Say you’re cutting a 50 ft × 3 ft × 4 ft service trench in dense clay. Bank volume is the geometric volume that came out:
Apply a 25% swell for clay loaded onto a tandem and the loose volume — what your hauler bills — comes out to:
At a 12 yd³ tandem box, that’s three loads with a partial on the third. Most haulers round up the partial to a full load, so plan and price as four if your dispatch is firm on the per-load rate.
Swell, and where the defaults come from
Soil swells when you dig it because the in-ground bond breaks up and air spaces open. Dense clay swells about 20-30%; sandy loam 10-20%; rock and shale 40-60%. The default 25% covers most residential clay-and-loam mixes — the kind of soil you hit on a typical southern-Ontario residential dig. If you’re cutting through topsoil, fill, or backfill someone else placed, set swell at the lower end; that material was already loose. Always confirm with your hauler if the load count drives the bid.
When to lean on it, when not to
This is a rectangular-prism calculator. It handles service trenches, footing cuts, sump pits, and small foundation cuts well. It is not the right tool for sloped cuts where the bottom width differs from the top, benched excavations, or anywhere the soil report flags variable layers. For those, calculate each prism separately or hand the takeoff to your contractor.
One cubic yard equals 27 cubic feet (≈ 0.76 cubic metres). Trucking, dump fees, and shoring are not in the calculator — confirm those with your hauler.
If you’re scoping anything where the soil report drives the schedule — utility crossings, rock cuts, or anywhere a dewatering plan kicks in — a sit-down with a contractor who can read the geotech is usually cheaper than budgeting against an assumption.
Other calculators on this site
If you’re scoping a whole project, you’ll usually need more than one of these. They share the same approach — plain math, honest about edge cases, with the practical notes someone who has done the work would actually need.
- Asphalt Calculator. Tonnage for a driveway, parking patch, or walkway pour, including the depth-to-tonnage curve a supplier will quote against.
- Concrete Pour Calculator. Cubic yards of concrete for a slab, footing, or post hole, plus the waste factor most pours actually need.
- Drywall Calculator. Sheets of drywall and bundles of mud for a renovation room, plus the cut and waste allowance.
- Fence Calculator. Lineal feet of fence, post count, rails, and gates for a property line that is rarely perfectly straight.
- Fill Calculator. Cubic yards of fill for a regrade, a backyard level, or a low spot, plus a sensible compaction factor.
- Lumber Calculator. Board feet for a deck, frame, or addition, in the rough framing pattern a supplier will price against.
- Paint Calculator. Gallons of paint for a room, plus the coverage difference between primed and unprimed surfaces.
- Tile Calculator. Square footage of tile for a floor or wall, plus the breakage and cut waste a real installation needs.
