How to Calculate Load Count for a Dirt Job in 5 Steps

Miscalculating the number of dump truck loads on a dirt job is one of the most expensive mistakes in earthwork contracting. Order too little fill and your project grinds to a halt while you scramble for more material. Order too much and you are paying to haul dirt away that you just paid to haul in. According to industry data from the AGC of America, material waste and logistics inefficiency account for a significant share of cost overruns on earthwork projects, making accurate load calculation a core competency for any contractor who wants to stay profitable.

Whether you are grading a residential lot, filling a commercial pad, importing topsoil, or moving cut material from an excavation, the math behind earthwork load calculation follows a consistent, repeatable process. In this guide, we walk through the precise 5-step method that experienced earthwork contractors and project managers use to convert raw volume measurements into accurate dump truck load counts. We cover soil swell and shrinkage factors, truck capacity variables, unit conversions, and the real-world adjustments that separate a tight bid from a costly mistake.

Why Accurate Load Count Calculation Matters

Before diving into the steps, it is worth understanding exactly what is at stake when load counts are wrong. On a medium-sized commercial pad project moving 5,000 cubic yards of fill, a 10 percent error in load count means 500 cubic yards of miscalculated material. At an average trucking cost of $150 to $250 per load in most U.S. markets in 2026, that error translates to roughly $7,500 to $12,500 in unexpected costs, before you account for labor delays, equipment idle time, or schedule penalties.

Accurate load counts also matter for regulatory and logistical reasons. Many municipalities and job sites impose truck traffic restrictions, requiring contractors to schedule haul windows carefully. If your load count is wrong, you may burn through your permitted haul hours without completing the job. On public road projects governed by Federal Highway Administration standards, inaccurate material quantities can trigger contract disputes and change order battles that drag on for months.

Finally, accurate calculation is essential for sourcing. When you know exactly how many loads you need, you can negotiate better rates with suppliers, coordinate truck scheduling efficiently, and avoid the premium pricing that comes with emergency material orders. Platforms like DirtMatch connect contractors with nearby verified dirt sources and project owners, making it easier to line up the right volume of material at the right time, often reducing sourcing costs significantly on larger jobs.

Key Terms You Need to Know Before You Calculate

Earthwork volume math uses a specific vocabulary that affects every calculation you make. Getting these terms straight before you start crunching numbers will save you from systematic errors that compound across a large job.

Bank Cubic Yards (BCY)

Bank cubic yards refers to material as it sits undisturbed in the ground, in its natural, compacted state. This is the baseline measurement for excavation. When a surveyor or engineer measures a cut volume, they typically report it in BCY.

Loose Cubic Yards (LCY)

When soil is excavated and loaded into a truck, it expands because air voids open up between the disturbed particles. This expanded volume is measured in loose cubic yards. Loose material always occupies more space than the same material did in the ground. This is why a truck can carry a certain number of LCY but that volume does not equal the same number of BCY.

Compacted Cubic Yards (CCY)

When fill material is placed and compacted at the destination, it typically compresses to a volume smaller than its bank state, depending on the soil type and the degree of compaction required. Compacted cubic yards is the final in-place volume after mechanical compaction.

Swell Factor

Swell factor is the percentage by which a soil expands when excavated from its bank state to its loose state. Sandy soils typically swell 10 to 15 percent. Common clays swell 20 to 30 percent. Rock, when blasted and excavated, can swell 30 to 40 percent or more.

Shrinkage Factor

Shrinkage factor describes how much a loose material compresses when placed and compacted compared to its bank state. A material with a 10 percent shrinkage factor means you need 1.1 BCY of source material to produce 1.0 CCY of compacted fill.

Understanding these factors is critical because trucks carry loose cubic yards, your design volumes are typically in bank or compacted cubic yards, and mixing up these units is the most common source of significant load count errors.

Step 1: Determine the Total Volume of Dirt Needed

The first step is establishing the total volume of material you are moving, in a consistent unit of measure. This number comes from one of three sources depending on the type of project.

Reading Engineering Plans

On commercial and civil projects, a licensed engineer or land surveyor will provide cut and fill volumes as part of the grading plan. These volumes are typically expressed in cubic yards and will specify whether the numbers represent bank, loose, or compacted material. Always confirm this with the engineer before starting your calculations. Using the wrong state of measure at this stage will cascade errors through every subsequent step.

Manual Volume Calculation

On smaller residential jobs or projects without formal engineering plans, you will calculate the volume yourself. For a simple rectangular fill area, the formula is:

Volume (cubic yards) = Length (ft) x Width (ft) x Depth (ft) / 27

The division by 27 converts cubic feet to cubic yards, since there are 27 cubic feet in one cubic yard.

For example, if you are filling a residential backyard that measures 60 feet long by 40 feet wide to an average depth of 1.5 feet:

60 x 40 x 1.5 = 3,600 cubic feet 3,600 / 27 = 133.3 cubic yards

For irregular areas, break the space into smaller geometric shapes (rectangles, triangles, trapezoids), calculate each section separately, and add the results together. For sloped or contoured grading jobs, the average-end-area method or prismatoid formula will give more accurate results, and these calculations are often handled with earthwork software or GPS machine control systems from companies like Trimble Construction.

Topsoil and Aggregate Projects

If you are importing topsoil, gravel, or aggregate rather than moving native soil, your volume requirement is typically expressed as the in-place compacted volume needed. You will apply shrinkage factors in Step 3 to work backward to the loose volume you need to order.

Step 2: Account for Swell and Shrinkage

This is the step where many contractors make their most costly mistakes. Volume in the ground does not equal volume in the truck, and volume in the truck does not equal volume after compaction. Each transition involves a conversion factor that must be applied correctly.

Standard Conversion Factors by Soil Type

The following table provides commonly used swell and shrinkage factors. These are industry-standard reference values used by earthwork engineers and estimators. Actual values can vary based on local soil conditions, moisture content, and compaction requirements, so always verify with a geotechnical engineer or soil test data for high-stakes projects.

To convert bank cubic yards to loose cubic yards (what goes in the truck): LCY = BCY x Swell Factor

To convert loose cubic yards back to bank cubic yards: BCY = LCY x Load Factor (Load Factor = 1 / Swell Factor)

To determine how many bank cubic yards of source material you need to achieve a target compacted volume: BCY Required = CCY Target / (1 - Shrinkage Factor expressed as decimal)

For a fill project targeting 500 CCY using common earth with a 15 percent shrinkage factor: 500 / 0.85 = 588 BCY of source material needed

Then converting that to loose yards for trucking: 588 x 1.27 (average swell) = 746 LCY to haul

Step 3: Convert Volume to Cubic Yards if Needed

All load count calculations should be standardized in cubic yards before proceeding. If your volume measurements are in cubic feet, cubic meters, or tons, convert them now.

Cubic Feet to Cubic Yards

Divide cubic feet by 27. 1,000 cubic feet / 27 = 37.04 cubic yards

Tons to Cubic Yards

This conversion requires knowing the material's bulk density, which varies considerably.

To convert tons to cubic yards: Cubic Yards = Tons / (Weight per cubic yard)

For example, 500 tons of moist common earth at 1.4 tons per cubic yard: 500 / 1.4 = 357 cubic yards

If you are sourcing material and the supplier quotes by the ton, this conversion is essential for reconciling your volume-based load count with the tonnage on your purchase order. Discrepancies between volume-based and weight-based measurements are a frequent source of billing disputes on dirt jobs, so document your conversion assumptions in writing.

Cubic Meters to Cubic Yards

For projects referencing metric measurements: 1 cubic meter = 1.308 cubic yards Multiply your cubic meter volume by 1.308 to get cubic yards.

Step 4: Determine Your Dump Truck's Carrying Capacity

Now that you have your total volume in loose cubic yards, you need to know exactly how many cubic yards each truck in your haul fleet can carry. This varies significantly by truck type, configuration, and local weight limits.

Common Dump Truck Capacities

Note that these are typical ranges. Actual legal payload is governed by state axle weight laws, bridge weight limits, and the specific truck's gross vehicle weight rating (GVWR) registered with the FMCSA. Overloaded trucks are a serious liability issue and subject to significant fines. Always confirm legal payload with your truck operator before bidding a job.

The Heaping Factor

In practice, most dump truck operators load their beds slightly heaped above the rated volume, particularly for lighter materials like topsoil. A heaped load can carry 10 to 15 percent more than the struck (level) capacity. However, for calculation purposes, it is best practice to use the struck capacity as your baseline and treat any heaping as a safety buffer, not as planned capacity. Using heaped loads in your base calculations creates risk if a scale check, job site inspector, or road restriction requires you to reduce loads mid-job.

Regional Weight Restrictions

Weight restrictions vary significantly by state and even by county road. Many states impose seasonal spring weight restrictions that reduce allowable axle loads by 20 to 40 percent during freeze-thaw periods. In mountain regions like those served by our dirt exchange in Denver, road grade and elevation compound weight limit considerations. Contractors in California, particularly those working on jobs connected to the dirt exchange in Los Angeles, must navigate strict state truck weight enforcement on many routes. Always verify local road restrictions before finalizing your truck selection and load count assumptions.

Step 5: Calculate Total Load Count and Build in a Buffer

With your total loose cubic yard volume and your per-truck capacity established, the core calculation is straightforward.

Total Loads = Total LCY / Truck Capacity (LCY per load)

Using our earlier example of 746 LCY to haul using tandem-axle trucks with a 12-cubic-yard struck capacity:

746 / 12 = 62.2 loads

Always round up to the next whole number, never down. 62.2 loads means 63 truck loads. Rounding down leaves you short.

Applying a Contingency Buffer

Experienced contractors add a 5 to 10 percent contingency buffer to their calculated load count to account for:

• Scale tickets that come in lighter than expected
• Material lost to spillage or handling inefficiency
• Soil moisture variations that affect density and volume
• Measurement errors in the original volume takeoff
• Compaction that falls short of target, requiring additional material

For our example: 63 loads x 1.08 (8 percent buffer) = 68 loads

This buffer is especially important when working with expansive clay soils or when importing topsoil with variable moisture content, since both materials can compact unpredictably. The USDA Web Soil Survey is a valuable free resource for understanding native soil types at your project location before you finalize your swell and shrinkage assumptions.

The Complete 5-Step Formula in Summary

1. Determine total volume needed (BCY, CCY, or tons from plans or manual takeoff)
2. Apply swell/shrinkage factors to convert to loose cubic yards
3. Convert all units to cubic yards if starting from cubic feet, tons, or meters
4. Identify per-truck capacity in cubic yards based on truck type and legal limits
5. Divide total LCY by per-truck capacity, round up, and apply a 5 to 10 percent contingency buffer

Putting It All Together: A Real-World Example

Let us walk through a complete, realistic example from start to finish.

Project: Commercial pad preparation for a retail building in a suburban market Task: Import fill to raise a 200-foot by 150-foot pad area by an average of 2.5 feet Soil Type: Imported sandy loam fill Truck Fleet: Tri-axle dump trucks, 16 cubic yards struck capacity

Step 1: Calculate design volume 200 x 150 x 2.5 = 75,000 cubic feet 75,000 / 27 = 2,778 CCY (compacted in-place target)

Step 2: Apply shrinkage factor to find BCY needed Sandy loam shrinkage factor: 0.92 (8 percent shrinkage) 2,778 / 0.92 = 3,019 BCY of source material required

Apply swell factor to find LCY to haul Sandy loam swell factor: 1.12 3,019 x 1.12 = 3,381 LCY to load and transport

Step 3: Units are already in cubic yards (no conversion needed)

Step 4: Confirm truck capacity Tri-axle truck, 16 CY struck capacity, verified within legal weight limit for moist sandy loam at approximately 1.2 tons/CY: 16 x 1.2 = 19.2 tons per load, within the truck's 24-ton legal limit. Capacity confirmed at 16 CY.

Step 5: Calculate load count with buffer 3,381 / 16 = 211.3 loads, rounded up to 212 212 x 1.08 (8 percent buffer) = 229 loads

Final Answer: Plan for 229 tri-axle truck loads to complete this job safely with adequate material contingency.

At a typical 2026 market rate of $180 per load for tri-axle hauling within a 20-mile radius, this job carries a trucking cost of approximately $41,220. The difference between a correct 229-load count and an under-calculated 190-load count would be a $7,020 shortage that could halt construction mid-job.

Common Mistakes That Blow Up Load Count Calculations

Even experienced contractors make the following errors repeatedly. Knowing them is the first step to avoiding them.

Forgetting to Apply Swell Factor

The most common and costly mistake: calculating load count directly from bank or compacted cubic yards without converting to loose cubic yards. If your design volume is 500 BCY of common clay and you calculate loads at 500 / 12 = 42 loads, you are ignoring the fact that those 500 BCY will occupy roughly 637 LCY in the trucks, requiring 53 loads. That is 11 missing loads, which could mean an entire day of additional trucking you did not budget for.

Using the Wrong Truck Capacity

Many contractors default to a round number like 10 cubic yards for every dump truck, regardless of the actual truck configuration. Using accurate, truck-specific capacity data is worth the extra five minutes of research. As shown in the capacity table above, the difference between a tandem-axle and a transfer truck is 14 or more cubic yards per load, which can more than halve your load count on a large job.

Ignoring Moisture Content Variations

Wet clay can weigh up to 1.8 tons per cubic yard. If your load count assumes 1.3 tons per cubic yard and your material is saturated, your trucks will hit weight limits before they hit volume capacity, reducing effective payload per load by 20 to 30 percent. After wet weather events, always reassess your load count assumptions before resuming hauling operations.

Not Accounting for Waste and Spillage

On large jobs with long haul distances, material spillage, truck washouts at the gate, and loader bucket inefficiency can collectively reduce effective material delivery by 3 to 7 percent. This is exactly what the contingency buffer is designed to cover.

Miscounting Cut vs. Fill Requirements

On balanced earthwork jobs (cut and fill from the same site), contractors sometimes calculate load counts for the fill placement but forget to separately calculate the export or reuse routing for the cut material. Each direction of movement is a separate load count calculation.

How Technology is Changing Earthwork Load Calculation in 2026

While the manual 5-step method described in this guide remains the professional standard for understanding and verifying calculations, technology has dramatically accelerated the process for large-scale projects.

GPS machine control and drone survey technology now allow contractors to capture site topography with sub-inch accuracy in a matter of hours rather than days. Earthwork software platforms automatically calculate cut-fill volumes, apply soil factor libraries, and generate truck load counts with just a few inputs. These tools are increasingly standard on commercial projects managed by members of the AGC of America.

However, technology does not eliminate the need to understand the underlying math. When software generates a load count, knowing how to verify that output against your manual calculation is the contractor's most important quality control step. Garbage in, garbage out applies to earthwork software just as it does to spreadsheets.

Beyond calculation, technology is also changing how contractors source and dispatch the material itself. If you are managing a large earthwork job and need to source fill dirt, export clean cut material, or find a nearby project that needs what you have, DirtMatch Pro connects earthwork contractors with verified material sources and receiving projects across the country, streamlining the logistics that follow from an accurate load count calculation.

Regional Considerations That Affect Load Count Planning

Load count calculations do not exist in a vacuum. Regional factors can significantly influence your assumptions and your final numbers.

Soil Type Variations by Region

Contractors working in the clay-heavy soils common in the southeastern U.S. face different swell and shrinkage challenges than those working in the sandy coastal soils of Southern California. The expansive soils in Colorado and the Front Range, familiar to contractors using the dirt exchange in Denver, require particular attention to moisture management and can swing shrinkage factors dramatically depending on seasonal conditions.

Seasonal Restrictions

Spring thaw weight restrictions in northern states reduce allowable truck payloads for 6 to 10 weeks each year. In affected regions, your effective truck capacity during this period may drop by 25 to 35 percent, which means your load count for the same volume goes up proportionally. Build this into your schedule and budget if your project spans the spring construction season.

Urban Haul Route Constraints

In dense urban markets like Boston or San Francisco, truck routing constraints, bridge weight limits, and permitted haul windows can force you to use smaller trucks that make more trips, or to stage material at an intermediate location. Contractors familiar with the dirt exchange in Boston and dirt exchange in San Francisco know that urban logistics add a layer of planning complexity that is not present on rural or suburban jobs.

From Load Count to Logistics: What Comes Next

Once you have your load count nailed down, the next phase is logistics planning. How many loads per day can your operation handle? How long does each truck cycle take (load, haul, dump, return)? Do you have enough loader capacity to keep trucks moving without creating a queue?

A common rule of thumb is that a single excavator or wheel loader can load one standard dump truck approximately every 5 to 8 minutes in good conditions. If your trucks have a 45-minute round trip cycle and you are targeting 30 loads per day, you need at least 5 to 6 trucks running to keep the loader busy and maintain your production rate.

Planning your load count is step one. Matching that count to a realistic daily production rate and hauling schedule is what transforms a good calculation into a successfully executed job. When you need to quickly find additional trucks, locate a nearby source for extra loads, or offload surplus excavated material to a compatible project, DirtMatch streamlines that matching process, connecting contractors, truckers, and project owners on a single platform built specifically for the earthwork industry.

Practical Checklist for Load Count Calculation

Before finalizing any load count for a bid or project plan, run through this verification checklist:

• Confirm whether design volumes are in BCY, CCY, or LCY
• Identify soil type and source material for accurate swell and shrinkage factors
• Verify actual truck configuration and legal payload with the hauling contractor
• Check state and local road weight restrictions for the planned haul route
• Convert all volumes to LCY before dividing by truck capacity
• Round final load count up, never down
• Apply a minimum 5 percent contingency buffer (8 to 10 percent for clay soils or uncertain conditions)
• Document all assumptions in writing for change order protection
• Cross-check volume-based load count against weight-based calculation if supplier quotes by the ton
• Revisit load count assumptions after any significant rain event that may have changed soil moisture

Following this checklist on every job, regardless of project size, is what separates contractors who consistently hit their material budgets from those who regularly absorb costly overruns.