Every construction project starts with a hole — and every hole starts with math. Before a single bucket of soil is moved, knowing exactly how much material you need to excavate, how it expands once dug, how many truckloads it takes to haul away, and what it will all cost is the difference between a smooth job and a budget disaster. This hub page gathers all ten excavation calculators on SiteCals and explains the formulas and soil science behind them.
Excavation touches nearly every construction project — foundations, basements, pools, utilities, driveways, and grading. It is also one of the most mis-estimated trades, because soil surprises beginners: a neat bank cubic yard of dense clay can grow by more than a third once dug and loaded. The calculators below account for exactly this, and this guide explains the concepts behind the numbers.
What Excavation Calculators Cover
The ten calculators in this category cover the full excavation workflow, from measuring what comes out of the ground to pricing the work. Volume tools estimate how much earth must be removed for a specific structure — Trench Volume Calculator, Excavation Volume Calculator, Basement Excavation Calculator, Pool Excavation Calculator, Footing Excavation Calculator, and Driveway Excavation Calculator. A grading specialist tool, the Cut and Fill Calculator, balances earthworks so you cut and fill the same ground with minimal import or export. Then the logistics and cost side is handled by the Spoil Swell Calculator, the Haul Away Calculator, and the Excavation Cost Calculator.
Together they answer four practical questions: how much material is involved, how big it gets once disturbed, how it moves off site, and how much it costs. For what goes into the hole afterward, see the foundation calculators, concrete calculators, and cost estimator calculators hubs.
When You Need an Excavation Calculator
Homeowners use these tools when pricing a pool, planning a basement dig-out, or getting driveway quotes — contractors quote by the cubic yard, so your own estimate lets you sanity-check theirs. Utility contractors run trench volumes daily: a 200 ft (61 m) trench at 5 ft deep is a very different job from the same trench at 6 ft deep, changing pipe bedding, spoil, and backfill quantities along with it.
During grading design, contractors use the cut-and-fill and swell tools to balance the site — moving earth from high spots to low spots costs far less than exporting it and importing fill later. Estimators use the cost calculator to build defensible bids, since mobilization, disposal fees, dewatering, and soil conditions can each swing the total. A five-minute estimate here reveals whether a quoted price is in the right ballpark.
A note on scope: these calculators handle the quantity and cost math. They do not replace a site survey, a soil report, or the local permits your area requires. Always call 811 (in the United States) or your local utility-locating service before any digging, and check with your local authority for trench safety and excavation regulations — OSHA trench rules apply to most excavation work deeper than 5 feet (1.5 m), and requirements vary by jurisdiction.
How to Use the Excavation Calculators
Each calculator follows the same simple pattern: enter your dimensions, pick your soil type where asked, and read the results. A few habits will make your estimates far more accurate:
- Measure in the right place. For trenches and footings, measure bottom width plus working room per side — excavators rarely dig exactly the pipe or footing width. Allow 1–2 ft (0.3–0.6 m) per side.
- Account for slope or benching. Safe trench walls in most soils must be sloped or benched as depth increases, which widens the top of the cut and adds volume. If your calculator accepts a slope ratio, use the one your local safety rules require rather than the raw trench width.
- Select the correct soil type. Soil type drives the swell factor and digging rate: sandy gravel digs fast and swells little; clay and rock dig slowly and swell a lot. When in doubt, use the more conservative (higher-swell) option.
- Work in one unit system per calculator. The tools accept imperial and metric inputs — pick one and stay consistent through the job so a mixed-unit mistake doesn’t inflate your estimate by an order of magnitude.
- Use the volume result downstream. The cubic-yard output from a volume calculator feeds directly into the swell, haul-away, and cost tools. Work the sequence in order: volume first, then swell, then haul-away, then cost.
Key Formulas and Concepts
The cubic yard formula
Excavation volume is almost always expressed in cubic yards (yd³) in the US, and cubic meters (m³) in metric countries. For a rectangular dig, the formula is simple:
Volume (yd³) = (Length × Width × Depth in feet) ÷ 27
Divide by 27 because one cubic yard equals 27 cubic feet. Example: a trench 100 ft × 3 ft × 5 ft = (100 × 3 × 5) ÷ 27 ≈ 55.6 cubic yards. In metric, 30 m × 0.9 m × 1.5 m = 40.5 m³ directly; for circular digs use π × r² × depth.
Bank cubic yards vs. loose cubic yards
This distinction causes more estimation errors than anything else in excavation. A bank cubic yard (BCY) is undisturbed soil in the ground; a loose cubic yard (LCY) is the same soil after digging — and it always takes up more space. The increase is called swell. You dig bank yards but you haul loose yards, so every truck and disposal estimate must use the swelled volume.
Swell factors by soil type
The percentage of swell depends on the soil. Commonly used planning ranges are:
| Soil / material type | Typical swell |
|---|---|
| Sand and gravel | 10–15% |
| Common earth (loam, silt mix) | 20–25% |
| Clay | 25–35% |
| Rock (blasted or ripped) | 40–60% |
The conversion: LCY = BCY × (1 + swell factor) — 100 BCY of clay at 30% swell becomes 130 LCY. See the Spoil Swell Calculator and our formula guide for worked examples. The reverse concept is shrinkage: compacted backfill typically occupies 10–20% less volume than it did in the truck, so plan backfill quantities accordingly.
Truckload math
Dump trucks are rated by loose cubic yards. Common capacities: a single-axle dump truck carries roughly 5–7 yd³, a tandem-axle truck 12–16 yd³, and a tri-axle or trailer combination up to 20+ yd³. The math is truckloads = loose cubic yards ÷ truck capacity, always rounded up. Continuing the earlier example: 55.6 BCY of common earth at 20% swell = 66.7 LCY, which is about 5 tandem-axle loads (66.7 ÷ 14 ≈ 4.8, rounded up to 5). The Haul Away Calculator runs this arithmetic for you, including cycle considerations.
Note trucks also have weight limits: wet, dense soil can hit the weight cap before the bed is volumetrically full — confirm with your hauler.
Excavation Cost Factors
Excavation is typically priced per cubic yard, per hour, or lump sum, varying widely by region, soil, and access. Key cost drivers captured by the Excavation Cost Calculator:
- Equipment rates. A mini-excavator with operator may cost a few hundred dollars per day; a full-size machine several times that. Harder soils mean slower production and more hours per yard.
- Mobilization. Transporting machines and crew is a fixed per-visit cost — a large share of small residential jobs.
- Disposal and dump fees. Tipping fees at quarries or landfills are charged per ton or load. Suspected contaminated soil costs far more to dispose of — get it tested.
- Dewatering. Digging below the water table requires pumps, well points, or sumps, plus the fuel and labor to run them. High groundwater can easily double the effective cost of a deep excavation.
- Access and working room. Tight lots, overhead wires, and hand-digging near utilities slow production. Rock work (ripping or hammering) is usually a separate, much higher line item.
- Backfill and compaction. Many quotes cover digging only; importing, placing, and compacting structural fill is a separate cost owners often overlook.
For a deeper breakdown of how these factors combine into a finished estimate, read our guide Excavation Cost Calculator: Cost Guide. And for the volume side of a general dig, the complete walkthrough is at Excavation Volume Calculator: Complete Guide.
Pro Tips for Accurate Excavation Estimates
- Verify dimensions on site, not just on plans. Grades change during construction; a final check with a tape and a level before ordering trucks prevents the most common shortfalls.
- Add a contingency. Experienced estimators add 10–15% to calculated volumes for overbreak — the extra soil that inevitably comes out beyond the neat theoretical lines, especially in rocky or unstable ground.
- Match the swell factor to the actual soil. Defaulting to “common earth” on a clay site underestimates haul-off by a full truck or more on a mid-size job. A handful of soil squeezed in your fist tells you a lot: gritty and loose is sand; smooth and sticky is clay.
- Plan the spoil pile location early. Swelled soil needs somewhere to sit. On tight lots, double-handling — moving a pile twice because it was dumped in the work zone — is pure wasted money.
- Separate rock from soil in your estimate. Even a small rock ledge priced at soil rates will wreck a budget. If test pits or neighbors’ experience suggest rock, price it as its own line item.
Browse All Excavation Calculators
Every excavation calculator on SiteCals, each with a one-line description:
- Trench Volume Calculator — Estimate cubic yards of soil removed for utility trenches, pipe runs, and drainage lines.
- Excavation Volume Calculator — Calculate general excavation volume for rectangular or circular digs in cubic yards or meters.
- Cut and Fill Calculator — Balance cut and fill quantities for grading so you minimize imported or exported earth.
- Basement Excavation Calculator — Estimate the dig volume, spoil, and haul-off for full or partial basement excavations.
- Pool Excavation Calculator — Work out excavation volume and overdig allowance for in-ground swimming pools.
- Footing Excavation Calculator — Calculate trench and pad footing excavation volumes including working room.
- Spoil Swell Calculator — Convert bank cubic yards to loose cubic yards using soil-specific swell factors.
- Haul Away Calculator — Turn loose-yard volumes into truckloads based on truck capacity.
- Excavation Cost Calculator — Build a line-item excavation estimate from equipment, labor, hauling, and disposal.
- Driveway Excavation Calculator — Estimate cut volume and base preparation quantities for new or replacement driveways.
Related Excavation Guides
Go deeper on the topics above with these step-by-step guides:
- Excavation Volume Calculator: Complete Guide — full walkthrough of measuring and calculating dig volumes.
- Spoil Swell Calculator: Formula Explained — bank vs. loose yards, swell tables, and worked examples.
- Excavation Cost Calculator: Cost Guide — every cost factor that turns a volume into a price.
Once the hole is dug, the next steps are covered in the foundation calculators hub, the concrete calculators hub, and the cost estimator calculators hub — or start from the SiteCals homepage to browse every category.
Excavation Calculators: Frequently Asked Questions
How do you calculate excavation volume in cubic yards?
Multiply length × width × depth in feet and divide by 27: (L × W × D) ÷ 27. Example: a 40 × 30 × 8 ft basement dig = 9,600 ÷ 27 ≈ 355.6 bank cubic yards. Break irregular shapes into rectangles and sum them, or use an average depth.
What is the difference between bank yards and loose yards?
BCY is undisturbed soil in the ground; LCY is the same soil after digging, when voids between broken clods add volume. You excavate bank yards but haul loose yards: LCY = BCY × (1 + swell factor), so 100 BCY of common earth at 20% swell becomes 120 LCY.
How much does soil swell after excavation?
It depends on soil type: sand and gravel typically swell 10–15%, common earth 20–25%, clay 25–35%, and blasted or ripped rock 40–60%. These are planning ranges — actual swell varies with moisture and how the material breaks up. For a fuller explanation with worked examples, see the Spoil Swell Calculator.
How many cubic yards does a dump truck hold?
Single-axle: 5–7 yd³; tandem-axle: 12–16; tri-axle or trailer combos: 20+. Divide loose cubic yards by capacity and round up. Wet, dense soil can hit weight limits before the bed is full — confirm with your hauler.
How much does excavation cost per cubic yard?
Costs vary widely by region, soil, depth, access, and disposal distance. Straightforward machine digging often lands in the tens of dollars per cubic yard in the US; rock, dewatering, or tight-access hand work costs several times more. Mobilization, dump fees, and backfill are often priced separately.
Do I need to call 811 before digging?
Yes — in the United States, call 811 (or your state’s one-call center) at least a few business days before any digging so underground utilities can be marked. Many jurisdictions require it by law, and striking a gas, electric, or fiber line is dangerous and expensive. Outside the US, contact your local utility-locating authority for the equivalent service.
What are the basic OSHA trench safety rules?
OSHA’s excavation standard generally requires protective systems — sloping, benching, shoring, or shielding — for trenches 5 feet (1.5 m) or deeper, a competent person to inspect the excavation, safe access and egress, and keeping spoil piles at least 2 feet back from the edge. This is a summary only, not legal guidance: always check the current regulations with your local authority and have excavations designed and supervised by qualified people.
How do I estimate cut and fill for grading?
Compare existing and proposed elevations on a grid: lower proposed grade means cut, higher means fill. A balanced site has roughly equal cut and fill, minimizing import/export. The Cut and Fill Calculator does the math — apply swell to exported cut and shrinkage (typically 10–20%) to compacted fill.
Should I add a contingency to my excavation estimate?
Yes. A 10–15% allowance on calculated volumes is standard practice to cover overbreak — soil that comes out beyond the neat theoretical excavation lines — plus measurement uncertainty and minor plan changes. On rocky, unstable, or poorly investigated ground, estimators often go higher. It is far cheaper to plan for an extra truckload than to mobilize equipment a second time.
What is the difference between excavation and backfill calculations?
Excavation math measures what comes out (bank yards, then swelled loose yards for hauling). Backfill math measures what goes back in: hole volume minus displaced pipes, footings, and structures, adjusted upward because compacted fill occupies 10–20% less than loose material. Run both so you order the right fill and schedule the right trucks.