The Earthwork Material Requirements Estimator calculates the compacted fill volume for a defined area and depth, then increases that quantity by an entered loose-to-compacted allowance. It can be used for preliminary borrow, imported fill, backfill, or grading quantity planning when the required finished fill geometry is reasonably uniform.
The compacted quantity comes from area multiplied by compacted depth. The allowance then increases the required loose material to recognize that placed material may occupy less volume after compaction. The correct factor depends on soil type, moisture, compaction specification, source condition, and measurement basis, so the percentage should come from project information or experience rather than a fixed rule. Irregular grades, stripping, unsuitable subgrade, settlement, and topsoil layers should be quantified separately when relevant.
Fill area, depth, and compaction allowance
sq ft
in
%
Result
—
loose cubic yards of fill required
Compacted fill volume—
Allowance volume—
Loose volume in cubic feet—
1. Enter fill area Use the plan area receiving the fill in square feet.
2. Enter compacted depth Enter the intended finished fill thickness in inches.
3. Enter loose-to-compacted allowance Use the percentage of extra loose volume needed to obtain the compacted volume.
4. Review required material The main result is the estimated loose cubic yards to procure or place.
5. Check the breakdown Compare compacted volume with the added allowance before carrying the quantity into cost or haul calculations.
Depth in feet = Depth in inches ÷ 12Compacted cubic feet = Area × Depth in feetCompacted cubic yards = Compacted cubic feet ÷ 27Loose required volume = Compacted cubic yards × (1 + Allowance % ÷ 100)
Where:
Area = fill footprint in square feet
Depth = compacted fill thickness
Allowance % = extra loose material needed relative to compacted volume
Assumptions: The model assumes a uniform fill depth across the entered area. The allowance is applied as a percentage increase over compacted volume and is not a laboratory-derived compaction curve.
What the result means
Use the result as a planning estimate tied to the inputs and assumptions shown above. Compare it with project-specific records, drawings, specifications, and field conditions before making commitments.
Inputs and production factors can vary by material, equipment, crew, measurement basis, and site conditions; update the assumptions when better project data is available.
Given:
Area = 10,000 sq ft
Compacted depth = 12 in
Loose-to-compacted allowance = 15%
Calculation: Depth = 12 ÷ 12 = 1 ft Compacted volume = 10,000 × 1 = 10,000 cu ft Compacted volume = 10,000 ÷ 27 = 370.37 cu yd Loose required volume = 370.37 × 1.15 = 425.93 cu yd Allowance volume = 425.93 − 370.37 = 55.56 cu yd
Result: 425.93 loose cu yd
The finished fill requires about 370.37 compacted cubic yards, and the entered allowance raises the loose planning quantity to about 425.93 cubic yards.
Is the allowance the same as a compaction percentage from a density test?
No. This input is a volume planning allowance. Laboratory or field density percentages use a different measurement basis and should not be substituted directly without confirming the relationship.
What if fill depth varies across the site?
Divide the site into zones with representative depths or use a detailed surface-volume method. A single average depth is best suited to preliminary uniform-scope estimates.
Can I enter zero allowance?
Yes. With zero allowance, the loose required volume equals the calculated compacted geometric volume.
Should topsoil be included?
Only if topsoil is part of the fill scope you are estimating. Structural fill, topsoil, aggregate, and other materials are often better quantified separately.
Why might delivered quantity differ from the result?
Truck measurement, moisture, source density, compaction behavior, spillage, grading tolerances, and field changes can all affect actual delivered or placed quantities.