TryBuildCalc

Excavation Cost Calculator (Earthwork Volume, Truck Loads & Cost)

Calculate excavation volume, loose soil, truck loads, and cost.

Inputs

Multiple Different-Sized Excavations?

ℹ️Typical: 10–40% (Sand ~15%, Clay ~30%, Rock ~60%)

ℹ️Used only to convert volume into an approximate weight in tons — does not affect volume, swell, or cost.

Enable Cost Estimation?

ℹ️Typical: 3-10 m³ per trip (about 105-350 cft per trip)

ℹ️Optional buffer added on top of the base cost for unexpected site conditions — commonly 5-15%.

You need approximately 375.000 (~600.00 t) of excavation, requiring 47 truck loads and costing around 187,500.

Calculations

Excavation Volume: 300.000 (~480.00 t)

Loose Volume: 375.000 (~600.00 t)

Swell Added: +75.00 (~120.00 t)

Estimates

Truck Loads: 47

Estimated Cost: 187,500

Tip: Metric tons use an approximate Ordinary / Mixed Soil density of 1.60 t/m³. Add 5-10% extra buffer to account for site variations and handling losses.

Approximate results for planning only. Verify with a professional.

Excavation Pit VisualizationGround LevelDepth = 1.5 mLength = 20 mWidth = 10 mExcavation Volume300.000 m³Loose Volume (with swell)375.000 m³Diagram simplified for clarity (not to scale)

Looking for the verification checklist, reference tables, or tips and mistakes?See the complete Rectangular Excavation Calculator.

Excavation cost estimate

This page keeps cost as the headline figure — a 20 m x 10 m x 1.5 m excavation gives 300 m³ of bank volume, becoming 375 m³ of loose soil after 25% swell, priced at a sample rate of 500 per m³ for an estimated total of 187,500.

At an 8 m³ truck capacity, that's 47 truck loads — cost, trucks, and volume all update together as you change any input, so you can see how a rate or swell change shifts the total budget.

  • Excavation: 20 m x 10 m x 1.5 m.
  • Rate: 500 per m³.
  • Estimated cost: 187,500.

How does excavation volume calculation work?

Excavation calculation involves determining the in-situ (original) soil volume, adjusting it for swell, and estimating transportation and cost requirements.

Step 1 — Calculate Excavation Volume

Volume = Length × Width × Depth
Total Volume = Volume × Number of Units
If sections differ in size: Total Volume = Sum of (Length × Width × Depth × Count) for every section

This gives the in-situ (original) volume of soil before excavation. All dimensions must be converted into meters. If you have several identical excavations (e.g. 5 matching footings), use the Number of Units multiplier. If your excavations are different sizes(e.g. 4 small footings plus 2 larger ones), switch on "Multiple Different-Sized Excavations" and enter each size as its own section — the calculator sums every section's volume into one total automatically.

Step 2 — Apply Swell Factor

Loose Volume = Excavated Volume × (1 + Swell %)

Soil expands after excavation due to loosening. This increase is called swell and depends on soil type:

  • Sand / Gravel → ~10–20%
  • Ordinary / Mixed Soil → ~20–30%
  • Clay → ~20–40%
  • Rock → ~50–80%

Step 3 — Calculate Truck Loads

Truck Loads = Loose Volume ÷ Truck Capacity (in m³)
If Truck Capacity is entered in cft: Truck Capacity (m³) = Truck Capacity (cft) ÷ 35.3147

This helps estimate how many trips are required to transport excavated soil from the site. Truck capacity can be entered directly in m³, or in cft (cubic feet) if that's how your vehicle or contractor quotes it — the calculator converts cft to its m³ equivalent first, then applies the same formula, so the result is identical either way.

Step 4 — Estimate Excavation Cost

Total Cost = Loose Volume (m³) × Cost per m³
If Cost is entered per cft: Cost per m³ = Cost per cft × 35.3147

Cost depends on soil type, labor, machinery, and site conditions. The cost rate can be entered per m³ or per cft — a cft rate is converted to its m³-equivalent rate before multiplying, since a cft rate is naturally a smaller number for the same total budget (1 m³ = 35.3147 cft).

Step 5 — Add Contingency (Optional)

Contingency Amount = Base Cost × (Contingency % ÷ 100)
Total Cost = Base Cost + Contingency Amount

Contingency is an optional buffer on top of the base cost to cover unexpected site conditions — hidden obstructions, unforeseen rock, weather delays, or price fluctuations. It defaults to 0%; a commonly used range is 5-15% depending on how well the site conditions are already known.

Example excavation calculation

This example uses the active calculator inputs above and follows the same steps from the formula section — showing the default scenario if you haven't changed anything, or your own live inputs once you do.

Input Values Used

InputValueWhy it is used
Dimensions20 m × 10 m × 1.5 mSets the in-situ excavation volume
Number of units1Multiplies volume for repeated identical excavations
Swell factor25%Converts in-situ volume into loose (haulage) volume
Equipment & cost8 /trip, 500 per Sets truck loads and total cost

Step 1 — Calculate Excavation Volume

CalculationSubstitutionResult
Volume per unit20 × 10 × 1.5300.000
Total volume300.000 × 1300.000

Step 2 — Apply Swell Factor

CalculationSubstitutionResult
Loose volume300.000 × (1 + 25/100)375.000

Step 3 — Truck Loads & Cost

CalculationSubstitutionResult
Truck loads375.000 ÷ 8.00 m³47 trucks
Base cost375.000 × rate187,500
Total costBase cost187,500

Therefore, this excavation needs approximately 375.000 of loose soil, requiring 47 truck loads and costing around 187,500.

This page keeps things focused on the calculation above. For the full construction guide — verification checklist, reference tables, usage steps, tips, common mistakes, and limitations.See the complete Rectangular Excavation Calculator.

Related Calculators

FAQ

Loose volume (375 m³, from 300 m³ bank volume x 1.25 swell) x 500 per m³ = 187,500. Cost is always based on the swelled, haulable volume, not the smaller bank volume.
Because loose volume represents the actual material being excavated, loaded, hauled, and disposed of — the swell allowance is real material handled on site, not a rounding margin, so pricing it into the cost avoids underestimating the budget.