What is the average end area method?

It approximates the volume of material between two cross-sections as the average of their areas times the distance between them: V = (A1 + A2) / 2 × L. It is simple and widely used for road and earthwork quantities, though it slightly overestimates volumes compared to the prismoidal formula for large tapering sections.

What is swell factor?

When soil is excavated it loosens and occupies more volume than in its undisturbed state. A swell factor of 1.15 means 1 m³ in-place becomes 1.15 m³ loose (bank cubic meters become loose cubic meters). Typical values: 1.10–1.30 for common soils, 1.30–1.80 for rock.

What is shrink factor?

When fill is compacted, it occupies less volume than in its undisturbed borrow state. A shrink factor of 0.90 means 1 m³ of compacted fill requires roughly 1/0.90 ≈ 1.11 m³ of bank (in-situ) borrow material to achieve. Values typically range 0.80–0.95 for soils.

Why can a station have both cut and fill areas?

On a typical cross-section the existing ground may be above the design grade on one side (cut) and below on the other (fill) in the same section. The cut area and fill area can coexist at the same station.

How accurate is this method?

For closely spaced stations (10–25 m) on moderately varying terrain, average end area is accurate to within a few percent. For widely spaced stations or rapidly changing cross-sections, the prismoidal formula or smaller station intervals will give better results.

What does net earthwork tell me?

Net earthwork = Total Cut − Total Fill (unadjusted). Positive means excess material that must be hauled away or stockpiled. Negative means a deficit — material must be imported from elsewhere or a borrow pit.

Earthwork Cut and Fill Calculator

Enter station cross-sections to compute cut and fill volumes using the average end area method, with swell and shrink factor adjustments.

Parameters

Units:

Swell Factor

Typical: 1.10–1.30

Shrink Factor

Typical: 0.80–0.95

Station
(m)

Cut Area
(m²)

Fill Area
(m²)

Total Cut

—

m³

Total Fill

—

m³

Net Earthwork (Cut − Fill)

—

Adjusted Volumes

Cut volume (loose) × swell factor —

Fill volume (bank) ÷ shrink factor —

Net adjusted —

Loose cut = excavated material volume at swell. Bank fill = in-place volume of material needed to achieve compacted fill.

Segment Summary

Segment	Length	Cut Vol	Fill Vol	Net

Enter at least two stations and click Calculate.

Cut and fill volumes will appear here.

Summary

This tool uses the average end area method to compute cut and fill volumes between consecutive survey stations. For each pair of adjacent stations, the volume equals the average of the two cross-sectional areas multiplied by the distance between them. Swell and shrink factors adjust raw volumes to reflect how excavated material expands and how placed fill compacts. Net earthwork is total cut minus total fill — a positive net means more excavation than fill; negative means you need to import material.

How it works

Select metric (m, m², m³) or imperial (ft, ft², ft³) units.
Enter the swell factor (excavated material expands, default 1.15) and shrink factor (compacted fill is denser, default 0.90).
Add at least two stations. Each station needs a chainage/stationing value plus a cut area and/or fill area.
Click Calculate. Between each adjacent pair of stations the tool computes: Cut volume = (A1_cut + A2_cut) / 2 × L and Fill volume = (A1_fill + A2_fill) / 2 × L.
Results show per-segment volumes, total project volumes, and adjusted volumes after applying swell and shrink factors.
Net earthwork = Total Cut − Total Fill (positive = net cut; negative = net fill required).

Use cases

Road and highway corridor grading quantity take-offs.
Dam embankment and reservoir cut/fill balance calculations.
Land development site grading estimates.
Railway alignment earthwork studies.
Check excavation and fill balance before bidding a construction contract.
Civil engineering coursework and exam practice.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu