What Is the Excavation Calculator?
The Excavation Calculator is a free online tool designed for contractors and DIY builders who need quick, accurate calculations in the construction and building space. By entering your length, width, depth, you get instant results including bank volume, swell volume, weight. No formulas to memorize, no spreadsheets to build — just enter your numbers and get the answer in seconds. Whether you're a beginner or experienced professional, this calculator saves you time and eliminates guesswork.
Why This Calculation Matters
Getting bank volume right can make the difference between success and costly mistakes. In construction and building, small errors compound quickly. Manual calculations are error-prone and time-consuming, especially under pressure. This calculator applies proven formulas used by contractors and DIY builders worldwide, giving you confidence that your numbers are correct. Use it to plan your projects with precision and avoid common pitfalls that trip up beginners.
When Should You Use This Calculator?
This tool is most useful when you know your length and need to find the right bank volume. It's also great for quick estimates before committing to a decision, and to double-check manual calculations or professional quotes, and when comparing different scenarios side by side. Bookmark this page and come back whenever you need a fast, reliable answer — the calculator is always free and requires no signup.
Excavation Calculator
Calculate dig volume and dirt hauling needs.
Excavation Volume by Dimensions
Loam soil, 25% swell factor, tandem truck (14 cu yd)
| Dimensions (L×W×D) | Bank Cu Yd | Loose Cu Yd | Weight (tons) | Truck Loads |
|---|---|---|---|---|
| 10×10×2' | 7.4 | 9.3 | 9.6 | 1 |
| 20×20×3' | 44.4 | 55.6 | 57.8 | 4 |
| 30×20×3' | 66.7 | 83.3 | 86.7 | 6 |
| 40×20×3' | 88.9 | 111.1 | 115.6 | 8 |
| 50×30×4' | 222.2 | 277.8 | 288.9 | 20 |
| 60×40×4' | 355.6 | 444.4 | 462.2 | 32 |
How to Use This Calculator
- Enter Your Length (feet): Start by entering your length — this is the primary input for the calculation.
- Fill In Additional Details: Complete the remaining fields: width, depth, soil type, dump truck size, hauling cost per load. Each value refines the calculation for greater accuracy.
- Click Calculate: Hit the Calculate button to run the numbers. Results appear instantly below.
- Review Your Results: Check your bank volume, swell volume, weight. Use these figures to inform your next decision or compare against alternative scenarios.
How It Works
This calculator computes excavation volume in bank (in-ground) cubic yards, then applies a swell factor to estimate the actual loose volume that needs to be hauled away.
The basic rule:
- Bank volume (cu yd) = length × width × depth ÷ 27 (volume in the ground)
- Swell factor: soil expands 20-40% when excavated (clay: 30%, sand: 15%, rock: 40%)
- Loose volume = bank volume × swell factor (this is what fills the trucks)
- Truck loads = loose volume ÷ truck capacity (round up to whole loads)
- Weight estimate: varies by soil type from 1.3 tons/cu yd (loam) to 1.8 tons/cu yd (rock)
Always factor in swell when estimating hauling needs — 100 cubic yards in the ground becomes 120-140 cubic yards on a truck. Disposal fees ($5-$15 per ton at most landfills) are additional. Some soils may need environmental testing before disposal.
Tips & Considerations
- Double-check your length before calculating — even small input errors can significantly change your results.
- Run the calculator with different values to compare scenarios and find the optimal approach for your situation.
- Pay attention to both bank volume and swell volume — they work together to give you the full picture.
- Bookmark this page for quick access next time you need to plan your projects.
- If you're unsure about your hauling cost per load, start with a conservative estimate and adjust from there.
Frequently Asked Questions
How many cubic yards is my excavation?
Cubic yards = length (ft) × width (ft) × depth (ft) ÷ 27. A 40×20×3 foot dig = 2,400 cu ft ÷ 27 = 88.9 bank cubic yards. After swell (25% typical), you'll have about 111 loose cubic yards to haul away.
What is swell factor in excavation?
Swell factor is how much soil expands when removed from the ground. Clay swells 30-40%, loam 20-30%, sand 10-15%, and rock 40-50%. This means 10 cubic yards in the ground becomes 13 cubic yards of loose soil on a truck.
How many truck loads to remove excavated dirt?
A standard tandem dump truck holds 10-14 cubic yards. For 100 loose cubic yards: 8-10 truck loads with a tandem. A tri-axle holds 16-18 cubic yards, reducing loads. Always calculate using loose (swell) volume, not bank volume.
How much does excavation cost per cubic yard?
Excavation costs $5-$15 per cubic yard for machine digging (mini excavator or backhoe). Hauling adds $15-$25 per cubic yard. Disposal fees add $5-$15 per ton. Total cost is typically $25-$50 per cubic yard including dig, haul, and disposal.
Do I need a permit to excavate?
Most jurisdictions require a permit for excavations deeper than 4 feet, any digging near property lines, or any dig that could affect neighboring structures. Always call 811 (Call Before You Dig) at least 3 days before any excavation to locate underground utilities.
Can I keep the excavated dirt on my property?
Yes, if you have space for it. Excavated soil can be used for grading, fill, raised gardens, or berms. However, it will take up 20-40% more space than the hole due to swell. Clay soil is poor for fill; sandy loam is preferred. Some soils (near gas stations, industrial sites) may be contaminated.