What is bank cubic yards (BCY)?

Bank cubic yards is the volume of material in its natural, undisturbed bank state before excavation — the baseline surveyed quantity used for excavation volume.

What is compacted cubic yards (CCY)?

Compacted cubic yards is the volume after mechanical compaction to the specified density (e.g., 95% Standard Proctor). CCY is typically 10-20% less than BCY due to air voids removed during compaction.

What is loose cubic yards (LCY) and swell?

Loose cubic yards is the swelled volume after excavation — BCY × (1 + swell%). Common earth swells ~20% (1.20), clay ~30% (1.30), rock up to 50% (1.50). LCY determines haul truck loads.

How do you convert BCY to CCY?

CCY = BCY × (1 - shrinkage%). Shrinkage comes from the geotechnical report (often 10% common earth, 15% clay). BidSync applies this per soil stratum from the DTM.

How does BidSync handle BCY vs CCY automatically?

BidSync builds a 3D DTM from contours/spot elevations, applies stripping/subsidence per soil stratum, then outputs BCY excavation, LCY haul, and CCY embankment balance directly to heavy civil assemblies with evidence links to plan sheets.

What happens if you get BCY/CCY wrong on a bid?

A 10% shrinkage error on a 20,000 BCY site is 2,000 CCY — either paying to export 2,000 CY you could have used as fill, or importing 2,000 CY at $15-30/CY plus trucking. The balance error alone can swing margin by $30k-60k.

BCY vs CCY — Bank Cubic Yards vs Compacted Cubic Yards

BCY = in-situ bank volume. CCY = volume after compaction. The difference is shrinkage — and getting it wrong breaks your earthwork balance and your margin.

Definitions

Bank cubic yards (BCY): Undisturbed, in-place volume as surveyed. Baseline for all excavation quantities and the unit pay item owners verify.
Loose cubic yards (LCY): Swelled volume after excavation — LCY = BCY × (1 + swell%). Determines haul truck loads and disposal cost.
Compacted cubic yards (CCY): Volume after compaction to specified density (often 95% Standard Proctor). CCY = BCY × (1 - shrinkage%). Used for embankment/fill pay.
Topsoil stripping (BCY): (Area × stripping depth) / 27 added to cut BCY — a frequent missed quantity that breaks balance.

Swell & Shrinkage Factors by Soil

Factors come from the geotechnical report. Typical ranges your estimator should verify per stratum:

Soil / Material	Swell (BCY→LCY)	Shrinkage (BCY→CCY)	LCY Factor
Common earth	20%	10%	1.20
Clay (heavy)	30%	15%	1.30
Sand & gravel	10%	5%	1.10
Solid rock	50%	0%	1.50

Example: 10,000 BCY common earth = 12,000 LCY to haul, = 9,000 CCY if used as fill.

Worked Example — 50,000 SF Site

Site 50,000 SF, avg cut 2.5 ft, avg fill 1.0 ft, stripping 4 in (0.33 ft), common earth (20% swell, 10% shrink):

Stripping BCY: (50,000 × 0.33) / 27 = 617 BCY
Cut BCY: (50,000 × 2.5)/27 + 617 = 4,630 + 617 = 5,247 BCY
LCY to haul: 5,247 × 1.20 = 6,296 LCY (÷ 16 CY/truck = 394 loads)
Fill CCY: (50,000 × 1.0)/27 = 1,852 CCY
Net balance: 5,247 BCY − 1,852 CCY = +3,395 BCY export (or 6,296 LCY − 1,852 CCY if comparing LCY to fill)

At $12.50/CY haul, export alone is ~$42k. Use the interactive cut & fill calculator to test your own numbers.

Common Mistakes That Cost Margin

Ignoring stripping: 4 in over 50k SF is 617 BCY you’ll pay to move but forgot to price.
Using one shrinkage for all strata: Rock (0%) vs clay (15%) on same site requires per-stratum DTM, not one global factor.
Mixing LCY and CCY in balance: Balance only BCY vs CCY, or LCY vs LCY — not BCY vs LCY.
No evidence trail: Owner remeasures. Without sheet/contour/DTM log, you eat the overrun.

How BidSync AI Handles BCY vs CCY Automatically

Upload vector PDF/DWG → automated contour detection (existing + proposed + breaklines) builds a 3D DTM → adjust stripping depth, subsidence, over-excavation, and per-stratum rock/soil factors → BidSync auto-calculates BCY excavation, applies swell to LCY for haul planning, converts to CCY via shrinkage for embankment balance, and pushes all three directly to heavy civil assemblies. Every cubic yard links to Plan C-302 / Detail W-14 / Spec 33 11 00 with transaction log — auditable cut/fill report for DOT and owners.

Bank cubic yards vs. compacted cubic yards

Definitions

Swell & Shrinkage Factors by Soil

Worked Example — 50,000 SF Site

Common Mistakes That Cost Margin

How BidSync AI Handles BCY vs CCY Automatically

Related Terms

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