This driveway excavation calculator works out how much dirt has to come out for a new asphalt driveway and how many trucks it takes to haul it. It sets the dig depth from the asphalt and base you will put back, adds topsoil stripping and soft-spot undercut, and converts the in-ground (bank) volume to the bigger loose volume that rides in the truck. It also checks truck weight, because damp clay often hits the legal payload before the bed is full.
Quick answer: dig depth = asphalt thickness + compacted base depth, plus any topsoil you must strip. Bank cubic yards = square feet × depth (in) ÷ 324. Multiply by 1.25 for typical earth to get the loose yards you haul.
A 12 × 50 ft driveway with 3 in of asphalt on 6 in of base, dug 6 in wider on each side (13 × 50 ft), is about 18.1 bank yd³, or 22.6 loose yd³ and about 29 tons of common earth: three tandem loads.
On this page
- How Deep to Dig for an Asphalt Driveway
- The Excavation Formula, Step by Step
- Swell vs Shrink: Bank, Loose and Compacted Yards
- Before You Dig: Utilities, Grade and Drainage
- Worked Examples
- What Does Driveway Excavation Cost?
- Tips for an Accurate Dirt Count
- Related Calculators
- Frequently Asked Questions
- Sources
How Deep to Dig for an Asphalt Driveway
Dig out the space the new pavement will fill: asphalt plus compacted base, typically 8 to 10 inches below the finished surface. Wisconsin DOT's standard driveway detail, for example, calls for removing material "to a depth sufficient to place 2" to 3" asphaltic surface and 6" base aggregate dense," and notes the base may be increased for clay subgrades. Topsoil or organic soil below that depth must go too.
| Project | Asphalt | Compacted base | Dig depth | Bank yd³ per 100 sq ft |
|---|---|---|---|---|
| Light-use pad or path | 2 in | 4 in | 6 in | 1.85 |
| Car driveway, firm soil | 2 to 3 in | 6 in | 8 to 9 in | 2.47 to 2.78 |
| Car driveway, clay or wet soil | 3 in | 8 in | 11 in | 3.40 |
| RV, delivery or truck traffic | 3 to 4 in | 10 to 12 in | 13 to 16 in | 4.01 to 4.94 |
Planning guidance (rule of thumb). Add any topsoil you strip; subtract any height the surface will sit above grade.
The Excavation Formula, Step by Step
- Dig footprint. Length × (paved width + 2 × over-dig). A 12 ft driveway with 6 in of over-dig each side is dug 13 ft wide, so 50 × 13 = 650 sq ft.
- Dig depth. Asphalt + base + extra stripping − height above grade. 3 + 6 = 9 in.
- Bank volume. Square feet × inches ÷ 12 ÷ 27, or simply ÷ 324. 650 × 9 ÷ 324 = 18.06 yd³. Add any undercut: area × undercut share × extra depth ÷ 324.
- Loose volume. Bank × (1 + swell). At 25%: 18.06 × 1.25 = 22.57 loose yd³.
- Weight. Bank yd³ × in-place lb per yd³ ÷ 2,000. At 3,200 lb: 28.9 tons. Digging adds volume, not weight.
- Truckloads. The larger of loose yd³ ÷ bed size and tons ÷ legal payload, rounded up. Tandem: 22.57 ÷ 12 = 1.9 by volume but 28.9 ÷ 14 = 2.06 by weight, so 3 loads.
Swell vs Shrink: Bank, Loose and Compacted Yards
Bank yards are measured in the ground, loose yards after digging (what fills a truck) and compacted yards after the soil is rolled into a fill. FHWA's Federal Lands design guidance: 1 cubic yard of earth in the cut may take 1.25 cubic yards in the truck and end up as only 0.65 to 0.85 cubic yards in an embankment. Swell is bank to loose; shrink is bank to compacted, which matters only if you reuse the soil as fill.
| Soil | Swell, bank to loose | In-place lb/yd³ | Loose lb/yd³ |
|---|---|---|---|
| Sand, dry | 11% | 2,880 | 2,590 |
| Gravelly soil | 20% | 3,280 | 2,730 |
| Common earth (rule of thumb) | 25% | 3,200 | 2,560 |
| Loam / earth, damp | 43% | 3,370 | 2,360 |
| Topsoil | 56% | 2,430 | 1,560 |
| Clay, dry | 50% | 3,220 | 2,150 |
| Clay, damp | 67% | 3,350 | 2,010 |
| Rocky soil, about half rock | 38% | 3,750 | 2,720 |
| Rock, ripped or blasted (sandstone) | 61% | 4,070 | 2,530 |
Swell and in-place weights from FHWA Federal Lands Exhibit 5.1 A, except common earth, which uses FHWA's 1.25 rule with a planning weight we chose between its dry (3,030) and damp (3,370) earth values. Loose weight = in-place ÷ (1 + swell). FHWA notes the factors are subject to about ±33% variation.
Truckloads: HomeGuide lists single-axle dump trucks at 5 to 8 yd³ and 6 to 8 tons, tandems at 10 to 14 yd³ and 12 to 18 tons, and tri-axles at 12 to 16 yd³ and 18 to 25 tons; the presets sit inside those ranges. Light topsoil fills the bed first, while dense, damp soil hits the payload first, so the calculator checks both. Ask your hauler for their real bed size and legal payload.
Before You Dig: Utilities, Grade and Drainage
- Call 811 a few business days ahead. 811 is the free national before-you-dig service. Contact it or your state 811 center a few business days before digging, wait until every utility has marked its lines, then dig carefully around the marks. Some lines are only inches deep.
- Shape the slope into the subgrade. Grade the bottom of the dig to the same fall as the finished surface so water drains off the base too. A common target is a 2% (about 1/4 inch per foot) cross slope or more; a contractor interviewed in the Asphalt Institute's magazine checks for 2 percent or more on residential driveways, and the Wisconsin DOT detail shows a 2.00% slope.
- Proof-roll and undercut soft spots. Run a loaded truck or roller over the subgrade; spots that rut or pump get dug deeper and refilled with stone. The undercut fields budget for that.
Worked Examples
Example 1: Single-car driveway, common earth
12 × 50 ft paved, 6 in over-dig each side, 3 in asphalt on 6 in base. Dig area 50 × 13 = 650 sq ft at 9 in: 650 × 9 ÷ 324 = 18.06 bank yd³. At 25% swell that is 22.57 loose yd³, and at 3,200 lb per bank yard it weighs 28.9 tons. A 12 yd³ / 14 ton tandem is weight-limited: 3 loads. The same footprint needs about 23.7 tons of crusher run base and the 600 sq ft of asphalt about 10.9 tons.
Example 2: Two-car driveway on damp clay with undercut
20 × 40 ft paved, 6 in over-dig, 3 in asphalt on 8 in base, and 10% of the area undercut a further 12 in. Dig area 40 × 21 = 840 sq ft. Main dig 840 × 11 ÷ 324 = 28.52 yd³, undercut 840 × 0.10 × 12 ÷ 324 = 3.11 yd³, total 31.63 bank yd³. Damp clay swells 67%: 52.82 loose yd³, weighing 53.0 tons. With 15 yd³ / 20 ton tri-axles, volume rules: 52.82 ÷ 15 = 3.5, so 4 loads. At a quoted $450 per load, hauling costs $1,800.
Example 3: Parking pad by area, sandy soil
A 1,200 sq ft dig footprint with 2 in asphalt, 4 in base and 4 in of topsoil to strip: 10 in deep, so 1,200 × 10 ÷ 324 = 37.04 bank yd³. Dry sand swells 11%: 41.11 loose yd³, weighing 53.3 tons. A 6 yd³ / 7 ton single-axle needs 7 loads by volume but 8 loads by weight. At $8 per bank yard to dig, excavation is about $296 before hauling.
What Does Driveway Excavation Cost?
HomeGuide's cost survey puts excavation at $2.50 to $15.00 per cubic yard including labor and equipment (light soil cheapest, heavy wet soil dearest), and $50 to $200+ where rock must be jackhammered. It lists excavating a driveway pad at $1,000 to $2,500 on average and moving dirt off site at $140 to $230 per cubic yard or $1,400 to $2,300 per truckload. Dump fees vary widely, so enter your own haul quote per load, loose yard or ton. For the full job, use the driveway cost calculator.
Tips for an Accurate Dirt Count
- Bank or loose? Digging is usually priced per bank yard (measured in place), hauling per load or loose yard. Make each quote say which.
- Order stone and asphalt from the same numbers. Base tons use the gravel base calculator defaults (1.5 t/yd³, 25% compaction, 5% waste) over the dig footprint plus any undercut. Asphalt uses 145 lb/ft³ over the paved area, before waste; fine-tune it in the asphalt calculator or, for multiple lifts, the asphalt tonnage calculator.
Related Calculators
Frequently Asked Questions
How much dirt do I need to remove for a driveway?
Multiply the dig footprint in square feet by the dig depth in inches and divide by 324 to get bank cubic yards. For a 12 × 50 ft driveway dug 13 ft wide and 9 in deep, that is about 18 yd³ in the ground, or about 22.6 yd³ in the truck once typical earth swells 25%.
How deep should I excavate for an asphalt driveway?
Dig to the asphalt thickness plus the compacted base depth, usually 8 to 9 in for a car driveway on firm soil (2 to 3 in of asphalt over 6 in of base). On clay or wet soil, or for heavier vehicles, plan 11 in or more, plus any topsoil or organic soil that sits below that depth.
What is the swell factor for dirt?
Swell is how much bigger soil gets when it is dug up. FHWA's general rule is that 1 yd³ of earth takes about 1.25 yd³ in a truck (25% swell). Its material table runs from about 5% to 11% for sand up to 50% to 67% for clay and over 60% for broken rock, with about ±33% variation.
How many cubic yards of dirt fit in a dump truck?
Roughly 5 to 8 loose yd³ in a single-axle, 10 to 14 in a tandem and 12 to 16 in a tri-axle. With dense or wet soil the legal weight limit is often reached first.
Do I need to call 811 before digging a driveway?
Yes. 811, the free national call-before-you-dig service, says every digging project, regardless of depth, needs a request a few days in advance so utilities can mark their lines.
Sources
- FHWA Federal Lands Highway, Earthwork Design (Exhibit 5.1 A, shrink and swell factors) (swell, in-place weights, 1.25 rule, ±33% variation).
- Wisconsin Department of Transportation, Standard Detail Drawing 9A15, Driveways (2 to 3 in asphalt on 6 in base; 2.00% slope).
- Asphalt magazine (Asphalt Institute), Commercial and Residential Paving, Part 2 (2 percent or more slope).
- 811, Call 811 before you dig (free; contact a few business days ahead).
- HomeGuide, Dump truck sizes and capacity (capacity by truck type).
- HomeGuide, Excavation cost (cost per cubic yard, dirt removal).
Last updated: October 2026 · How we calculate