How to use the excavation calculator calculator
- 1
Arrange utility location first
Follow the utility-location procedure that applies where you are before any digging starts. This is a legal and safety step, not an optional one.
- 2
Split the dig into sections
Add a section for each part of the excavation. A basement with a separate garage dig is two sections, and an area where the depth changes is best split rather than averaged by eye.
- 3
Enter the average depth of each part
For a cut of uniform slope, the average of the depths at each end gives the correct volume. For anything more irregular, use more sections.
- 4
Add a swell allowance for hauling
In-place soil occupies less space than the same soil loose in a truck. The increase depends heavily on the material, so enter a figure appropriate to your soil rather than relying on a default.
- 5
Add your haulage pricing
Enter your quoted price per cubic yard and any mobilization or disposal fee for an estimated total.
Formula
Excavation cubic yards = (area(sq ft) x depth(ft)) / 27
The result is bank, or in-place, volume. Multiply by a swell factor of your own to estimate the loose volume that has to be hauled.
Worked example
An excavation 30 feet by 20 feet, 4 feet deep
- 1Find the area: 30 x 20 = 600 square feet.
- 2Find the volume: 600 x 4 = 2,400 cubic feet.
- 3Convert to cubic yards: 2,400 / 27 = 88.89 cubic yards.
The dig removes about 88.89 cubic yards measured in place. The loose volume to haul away is larger.
Worked examples
What a swell allowance does to the haulage
The same 88.89 cubic yards with a 25 percent swell allowance
- 1In-place volume: 88.89 cubic yards.
- 2With 25 percent swell: 88.89 x 1.25 = 111.11 cubic yards loose.
- 3Difference: 22.22 cubic yards of extra truck space.
The 25 percent is a figure chosen for this example, not a published rate. Soil genuinely bulks up when excavated, but the amount varies widely by material, so ask your contractor or haulier what to expect.
An excavation with two depths
A 600 square foot dig where 400 square feet is 4 feet deep and 200 is 2 feet deep
- 1Deep section: 400 x 4 = 1,600 cubic feet.
- 2Shallow section: 200 x 2 = 400 cubic feet.
- 3Total: 2,000 cubic feet, or 74.07 cubic yards.
- 4Averaging the depth instead: 600 x 3 = 1,800 cubic feet, or 66.67 cubic yards.
Averaging the depth across unequal areas understates this dig by 7.4 cubic yards. Sections are more accurate whenever the areas at each depth are not equal.
Cut volume, loose volume, and compacted volume
Earthwork involves the same material in three states, and each has a different volume. Getting them confused is the most common source of error in an excavation estimate.
Bank or in-place volume is the material as it sits in the ground, and it is what the geometry gives you. Loose volume is the same material after excavation, which is larger because digging introduces voids: that is the volume that fills trucks. Compacted volume is the material after it has been placed and compacted somewhere else, which is typically smaller than the bank volume.
So a dig that removes 89 cubic yards in place might fill well over 100 cubic yards of truck space, and if that same soil were used as engineered fill elsewhere it might end up occupying less than 89. Each figure answers a different question: how big is the hole, how many loads is that, and how much fill do I have.
Why no swell factor is published here
Swell varies enormously with the material. Loose sand behaves nothing like dense clay, and rock behaves differently again. Moisture content matters, as does how the material is excavated and handled.
Published tables of swell percentages exist, and they are useful in the hands of someone who knows which row applies to the ground in front of them. Baked into a general calculator as a default, they mislead more often than they help, because most users will not know whether the assumed figure matches their soil.
So the allowance field starts empty. If you know the soil, enter a figure for it. If you do not, ask the contractor or haulier who will move it, since they will have a view based on local material.
Sections beat averaging
The temptation on an uneven dig is to take an average depth and multiply once. That is exactly right when the areas at each depth are equal, and wrong the rest of the time.
The worked example above shows why: averaging 4 feet and 2 feet to 3 feet across 600 square feet gives 66.67 cubic yards, while calculating a 400 square foot deep section and a 200 square foot shallow one gives 74.07. The average ignores that more of the area is at the greater depth.
The exception worth remembering is a uniform slope, where the depth changes smoothly from one end to the other. There the average of the two end depths is exactly correct, because the volume above and below the average cancel out.
Turning volume into truck loads
Haulage is usually the practical constraint on an excavation, and it is priced by the load or by the cubic yard rather than by the hole.
To get from your figure to loads, you need the loose volume rather than the in-place volume, and you need to know what a truck actually carries. YardCalc publishes no truck capacity, because it varies by vehicle and by local weight limits, and a truck that is full by volume may be over its legal weight with dense material long before it is full.
Ask your haulier what their trucks carry for your material, then divide your loose volume by that. The dump truck capacity guide covers the geometric side of bed capacity if you want to check a figure.
Common mistakes
Where excavation estimates go wrong:
- Using the in-place volume to order haulage, when loose material takes more space.
- Averaging depth across unequal areas instead of using sections.
- Applying a swell factor found online without knowing whether it fits the soil.
- Assuming a truck capacity rather than asking the haulier.
- Forgetting that a truck full by volume can be overweight with dense material.
- Measuring the finished floor area rather than the full extent of the dig, which usually extends beyond it.
- Digging before arranging utility location.
Sources and methodology
Every figure on this page comes from geometry, not from a product or materials database. Areas use the standard area formulas, volumes are area multiplied by depth, cylinders use pi times the radius squared times the height, and unit conversions use exact factors: 12 inches to a foot, 27 cubic feet to a cubic yard, and 9 square feet to a square yard.
YardCalc publishes no material density, coverage rate, product dimension, soil swell factor, compaction factor, or price. Those vary by product, by supplier, by soil, and by region, and a figure that is right in one case is wrong in another, so the calculator asks you for the values that apply to your job. Weight estimates appear only when you supply a density.
Nothing here is engineering, safety, or code guidance. Results are planning estimates. Read how every value on the site is derived and checked in the YardCalc calculation methodology.
Excavation cubic yards by area and depth
In-place volume for a given area at a given depth, before any swell allowance. Depth columns are reference values, not recommendations.
| Area | 12 in | 18 in | 24 in | 36 in | 48 in | 60 in |
|---|---|---|---|---|---|---|
| 100 sq ft | 3.7 | 5.56 | 7.41 | 11.11 | 14.81 | 18.52 |
| 200 sq ft | 7.41 | 11.11 | 14.81 | 22.22 | 29.63 | 37.04 |
| 400 sq ft | 14.81 | 22.22 | 29.63 | 44.44 | 59.26 | 74.07 |
| 600 sq ft | 22.22 | 33.33 | 44.44 | 66.67 | 88.89 | 111.1 |
| 800 sq ft | 29.63 | 44.44 | 59.26 | 88.89 | 118.5 | 148.1 |
| 1,000 sq ft | 37.04 | 55.56 | 74.07 | 111.1 | 148.1 | 185.2 |
| 1,500 sq ft | 55.56 | 83.33 | 111.1 | 166.7 | 222.2 | 277.8 |
| 2,000 sq ft | 74.07 | 111.1 | 148.1 | 222.2 | 296.3 | 370.4 |
Frequently asked questions
- How do I calculate excavation volume?
- Multiply the excavation area by the depth to get cubic feet, then divide by 27 for cubic yards. A 30 by 20 foot dig 4 feet deep is 2,400 cubic feet, or 88.89 cubic yards in place.
- How many cubic yards in a 20 x 20 excavation?
- A 20 by 20 foot area is 400 square feet. At 2 feet deep that is 29.63 cubic yards, at 4 feet 59.26 cubic yards, and at 6 feet 88.89 cubic yards, all measured in place.
- What is soil swell and why is no factor included?
- Excavated soil bulks up once loosened, so the loose volume exceeds the in-place volume. How much depends on the material, the moisture, and the handling, so YardCalc applies no factor. Enter one appropriate to your soil, or ask your contractor.
- Should I average the depth or use sections?
- Use sections whenever the areas at each depth differ. Averaging is exactly right only for a uniform slope or when the areas are equal; otherwise it can understate the volume noticeably.
- How many truck loads will my excavation be?
- Divide the loose volume, not the in-place volume, by what your truck actually carries. YardCalc publishes no truck capacity, since it varies by vehicle and local weight limits, and dense material can put a truck over weight before it is full.
- Does this include the cost of hauling?
- Only if you enter your own rate. The calculator applies a price per cubic yard and any fixed fee that you supply; it publishes no haulage prices.
Excavation volume is your measured area multiplied by the depth you enter, converted at exactly 27 cubic feet per cubic yard, and reported as in-place volume. No soil swell factor, truck capacity, or haulage price is assumed, and this page provides no excavation safety or regulatory guidance. Quantities come from exact geometry using the dimensions you enter. Confirm product dimensions, installation requirements, local codes, site conditions, safety requirements, and final order quantities with the appropriate manufacturer, supplier, contractor, or professional.
Results are planning estimates. Last reviewed 2026-07-28.