How to Calculate Cubic Yards of Dirt for Excavation and Fill

In the dirt business, volume is money. Order too little fill and you are paying a minimum load charge to bring a truck back out. Order too much and you are paying to import material that ends up as a stockpile in the corner of the site. On the disposal side, overestimating spoils means renting more dumpsters or trucks than you need. Underestimating means your crews sit idle while you scramble for a place to put material. Neither scenario is acceptable when you are trying to hit a bid number.

The core problem is that a cubic yard of dirt is not a fixed quantity. A cubic yard in the bank weighs roughly 1.3 to 1.5 tons depending on moisture and soil type. Once you dig it, it fluffs up and takes more space. Once you compact it, it shrinks back down. If you calculate a neat rectangle and order that number, you will almost always be wrong.

This guide is built for working contractors who need fast, field-ready math. You will learn how to calculate cubic yards of dirt for excavation, grading, and fill, how to convert between bank, loose, and compacted volumes, how to estimate cut-and-fill balance, and how to translate all of it into truckloads and dump-site tickets. Whether you are buying fill dirt on NeedsDirt.com or booking a dump site for spoils, the numbers you run here determine whether the job makes money.

Before you touch a calculator, you need to understand the three volume states that dirt moves through on a job. Every excavation and fill estimate starts here.

• Bank cubic yard (BCY): The volume of dirt in its natural, undisturbed state before you dig it. This is what you calculate from a topographic survey, a test pit, or a plan sheet with existing and proposed grades.
• Loose cubic yard (LCY): The volume after excavation. Digging breaks the soil apart and adds air voids, so the same weight of material occupies more space. The ratio of loose to bank volume is called swell.
• Compacted cubic yard (CCY): The volume after the material is placed and compacted in lifts. Compaction squeezes out air and rearranges particles, so the volume shrinks relative to loose and often relative to bank. The ratio of compacted to bank volume is called shrink.

Typical swell factors range from 10 to 35 percent for common soils. Sand and gravel might swell 10 to 15 percent. Common clay and loam often swell 20 to 30 percent. Rocky or highly fractured material can swell 30 to 45 percent. Shrink factors are usually expressed as a percentage of bank volume and commonly run 5 to 15 percent for well-compacted structural fill.

Here is the practical takeaway. If you dig 100 BCY of clay with a 25 percent swell, you will haul roughly 125 LCY. If that same material is placed as compacted fill with a 10 percent shrink, it will occupy about 90 CCY. The dirt did not disappear or appear. It changed state, and your truck counts and purchase quantities must change with it.

Rule of thumb: estimate in bank yards for excavation, order in loose yards for import, and specify in compacted yards for structural fill.

When you are sourcing fill on NeedsDirt.com, confirm whether the seller is quoting bank, loose, or compacted yards. Most bulk listings quote loose yards because that is what the truck carries. If a broker quotes you bank yards, convert before you compare prices.

The basic formula for any prism-shaped volume is length times width times depth in feet, divided by 27 to convert cubic feet to cubic yards. For a rectangular pad, that is straightforward. For real jobsites, you need a few more tools.

Rectangular and square areas: Measure length and width in feet. Convert depth from inches to feet by dividing by 12. Multiply L x W x D, then divide by 27. Example: a 40 ft by 60 ft pad at 6 in. deep is 40 x 60 x 0.5 = 1,200 cubic feet, divided by 27 = 44.4 cubic yards. That is bank volume if you are cutting, or compacted volume if you are filling to that grade.

Circular areas: Use pi times radius squared times depth. For a 20 ft diameter circle at 1 ft deep, radius is 10 ft, so 3.1416 x 100 x 1 = 314.16 cubic feet, divided by 27 = 11.6 cubic yards.

Irregular shapes: Break the area into rectangles, triangles, and circles. Calculate each separately, then add them. For a triangle, use 0.5 x base x height x depth. For long strips like utility trenches or footings, treat them as long rectangular prisms and measure in linear feet.

Sloped or varying depth: If depth changes across the area, average the shallow and deep ends. A trench that starts at 2 ft and ends at 6 ft has an average depth of 4 ft. This is accurate enough for most bidding, but for large earthwork, use cross-sections every 25 to 50 ft and average the end areas, a method called average end area.

Field measurement tips: Use a laser level or a rotary level with a story pole to check existing grade. A string line and a line level work for short runs. For larger sites, a drone survey or a GPS rover gives you cut and fill volumes directly. Always measure in feet and convert inches to decimals before you multiply. Six inches is 0.5 ft, 4 in. is 0.33 ft, 9 in. is 0.75 ft.

Once you have your bank or compacted volume, apply swell or shrink to get the number you actually order or haul. If you need 100 CCY of fill and your material shrinks 10 percent from bank, you need about 111 BCY, which swells to roughly 139 LCY at 25 percent swell. That is the number that goes on the truck ticket.

The cheapest dirt is the dirt already on your site. A cut-and-fill balance means you use material from high areas to fill low areas, minimizing both import and export. The calculation is simple: total cut volume minus total fill volume. If cut exceeds fill, you have a surplus to export or stockpile. If fill exceeds cut, you have a deficit to import.

But you cannot compare bank cut yards directly to compacted fill yards. Convert everything to a common state first. The cleanest approach is to convert both to bank yards.

• Cut volume is already in bank yards if measured in place.
• Fill volume is usually specified in compacted yards. Convert to bank by dividing by the shrink factor. For 10 percent shrink, divide CCY by 0.90. For 15 percent shrink, divide by 0.85.
• Subtract adjusted fill from cut. A positive number is surplus, a negative number is deficit.

Example: You calculate 500 BCY of cut and 600 CCY of fill. With 10 percent shrink, 600 CCY divided by 0.90 equals 667 BCY of fill needed. Your deficit is 167 BCY. You will need to import at least 167 bank yards, which becomes about 209 loose yards at 25 percent swell.

Do not forget topsoil. Strip and stockpile topsoil separately. It is usually 4 to 8 in. deep and should not be counted as structural fill. If you strip 6 in. of topsoil from a 5,000 sq ft area, that is 5,000 x 0.5 = 2,500 cubic feet, or about 93 cubic yards of stockpiled topsoil to respread later.

Also account for waste and over-excavation. Most contractors add 5 to 10 percent to import quantities to cover spillage, uneven subgrade, and minor over-dig. If you are placing fill on soft ground, you may need to over-excavate and replace unsuitable material, which adds volume to both cut and fill.

When you have a surplus, list it as a fill dirt source on NeedsDirt.com or find a dump site near you to dispose of it. When you have a deficit, browse fill dirt listings on NeedsDirt.com and compare delivered prices per loose yard.

Swell and shrink are not guesses. They are measurable properties that vary by soil classification, moisture content, and compaction method. Using the right factor can swing your truck count by 20 percent or more.

Here are typical ranges you can use for bidding when you do not have a geotech report:

• Sand and gravel: Swell 10 to 15 percent. Shrink 5 to 10 percent. These materials compact well and drain fast.
• Silty sand or sandy loam: Swell 15 to 20 percent. Shrink 8 to 12 percent. Common in residential grading.
• Clay and silty clay: Swell 20 to 30 percent. Shrink 10 to 15 percent. These are the most common fill materials and the most sensitive to moisture.
• Heavy clay: Swell 25 to 35 percent. Shrink 12 to 18 percent. Difficult to compact without moisture control.
• Rock, shale, and fractured bedrock: Swell 30 to 45 percent. Shrink 10 to 20 percent depending on fragment size and compaction.
• Organic silt or topsoil: Swell 20 to 35 percent. Shrink 15 to 25 percent. Not suitable for structural fill.

Moisture content changes everything. Wet clay can swell 30 percent or more and may not compact at all until it dries. Dry sand may barely swell 10 percent but will not hold a slope. If you are placing structural fill, a Proctor test gives you the maximum dry density and optimum moisture content. From that, you can calculate the exact bank-to-compacted conversion for your material.

Here is the field formula for shrink: compacted volume equals bank volume times one minus shrink percentage. For 100 BCY and 12 percent shrink, CCY = 100 x 0.88 = 88 CCY. For swell: loose volume equals bank volume times one plus swell percentage. For 100 BCY and 25 percent swell, LCY = 100 x 1.25 = 125 LCY.

If you are buying fill from a NeedsDirt.com listing and the seller does not know the swell factor, ask for the soil type and assume the middle of the range. Then add 5 percent to your order. It is cheaper to have a little extra on site than to pay a second delivery fee.

Dirt moves by truck, and truck capacity is rated in cubic yards, tons, or both. You need to know which limit controls your load.

A standard tandem-axle dump truck carries 10 to 14 cubic yards loose, but weight limits often cap it lower. At 1.3 tons per loose yard, 12 yards weighs 15.6 tons. Many jurisdictions limit tandem axles to 13 to 15 tons gross payload, so you may only legally haul 10 to 11 yards of heavy clay. Sand and gravel at 1.4 to 1.5 tons per yard may limit you to 9 or 10 yards.

A tri-axle dump truck carries 16 to 20 cubic yards loose, with payload limits around 20 to 22 tons. A semi-end dump or transfer trailer can carry 20 to 26 cubic yards, subject to bridge and axle laws. A dumpster or roll-off container is rated in cubic yards but should not be filled above the rim for heavy dirt.

Use this process to convert your volume to loads:

• Calculate your loose yards. If you have bank yards, multiply by one plus the swell factor.
• Determine the controlling capacity. Compare the truck bed volume to the legal payload divided by material density. The lower number wins.
• Divide total loose yards by the controlling capacity per load and round up.
• Add one load for contingencies on small jobs, or 5 percent on large jobs.

Example: You need to import 150 LCY of clay at 1.3 tons per yard, total 195 tons. A tandem truck legally limited to 14 tons can haul 10.8 yards by weight, but the bed holds 12. The controlling number is 10 yards per load. You need 15 loads. At 12 yards per load you would only need 13 loads, but you would be overweight and risking fines.

On the disposal side, dump sites and transfer stations charge by the ton or by the yard. A 20-yard dumpster of clay can weigh 20 to 26 tons, which may exceed the hauler weight limit. Always ask the dump site whether they charge by weight or volume and whether they have a per-truck limit.

When you book hauling or find a dump site near you on NeedsDirt.com, give the hauler your loose yard total and the soil type. They will match the right truck to the job and give you an accurate per-load price.

Once your numbers are solid, the transaction is straightforward. NeedsDirt.com connects contractors with fill dirt sources, dump sites, and excavation material listings in their area. The platform works best when you bring accurate volumes and clear specifications.

When you list a need or browse fill dirt listings, include these details:

• Total loose yards needed, plus your swell assumption.
• Soil type required: clean fill, structural fill, sandy loam, clay, or select fill.
• Compaction requirement: 95 percent Standard Proctor, 90 percent, or none.
• Access constraints: gate width, overhead wires, weight restrictions, and dump height.
• Timeline and whether you need the seller to haul or you will pick up.

When you book a dump site for spoils, provide the loose yard total, soil type, and any contamination status. Clean dirt, concrete, asphalt, and mixed demolition debris are priced differently. Some sites accept only clean fill. Others accept rock and concrete for a higher tipping fee. Knowing your material classification before you call prevents rejected loads and wasted trips.

Price expectations vary by region, but here are typical ranges to sanity-check your bids. Clean fill dirt from a local source often runs 10 to 25 dollars per loose yard picked up, or 25 to 50 dollars per yard delivered within 10 miles. Dump site tipping fees for clean dirt commonly run 10 to 30 dollars per ton, or 100 to 300 dollars per 20-yard load depending on weight and local market. Hauling adds 75 to 150 dollars per hour or 10 to 20 dollars per loaded mile.

Always confirm whether the price is per bank, loose, or compacted yard. A quote of 20 dollars per bank yard can be more expensive than 25 dollars per loose yard once you convert. If a seller cannot tell you the swell factor, assume 25 percent for clay and 15 percent for sand.

Keep your ticket stubs and scale tickets. They are your proof of quantity if a dispute arises, and they help you true up your estimate for the next job. Over time, you will build a personal swell and shrink library for your region that makes your bids sharper than the competition.

Keep this cheat sheet in your truck. It covers the math you will use every day.

• Cubic feet to cubic yards: divide by 27.
• Inches to feet: divide by 12. 6 in. = 0.5 ft, 4 in. = 0.33 ft, 9 in. = 0.75 ft.
• Bank to loose: multiply by one plus swell. 100 BCY at 25 percent swell = 125 LCY.
• Bank to compacted: multiply by one minus shrink. 100 BCY at 10 percent shrink = 90 CCY.
• Compacted to bank: divide by one minus shrink. 90 CCY divided by 0.90 = 100 BCY.
• Loose to bank: divide by one plus swell. 125 LCY divided by 1.25 = 100 BCY.
• Tons to yards: divide tons by density in tons per yard. 20 tons divided by 1.3 = 15.4 LCY.
• Rectangle volume: L x W x D divided by 27.
• Circle volume: 3.1416 x radius squared x depth divided by 27.
• Triangle volume: 0.5 x base x height x depth divided by 27.

Common mistakes that cost contractors money:

• Mixing bank and loose yards in the same estimate. Always convert to one state.
• Forgetting topsoil strip volume. It adds to spoils and must be respread.
• Ignoring compaction shrink when importing fill. You will run short every time.
• Using bed volume instead of legal payload for truck counts. Weight limits control heavy dirt.
• Not adding waste allowance. Five to 10 percent covers spillage and over-dig.
• Assuming a dump site charges by volume when they charge by weight. A 20-yard load of wet clay can weigh 26 tons.
• Failing to confirm swell factor with the fill supplier. Ask for the soil type and moisture condition.

If you want a faster path, use a cubic yard calculator for excavation to check your hand math, then verify with a second method. For simple rectangles, the math is quick. For complex sites, break the area into shapes and add them up. When your numbers are ready, find fill dirt on NeedsDirt.com or browse dump sites near you to turn your calculation into a scheduled delivery or disposal.