Cut and Fill Calculator — How to Calculate Earthwork Volume

Posted April 17, 2026 | Heavy Equipment | Math | Read time: 12 min

The complete guide to cut and fill math — formulas, swell factors, truck loads, and the mistakes that cost operators thousands every year.

Every construction job that moves dirt lives or dies on cut and fill math. Bid it wrong and you lose money before you turn the first track. Calculate it wrong and you under-truck the job. Forget swell factor and you're short on hauling capacity by 25%.

What "Cut and Fill" Actually Means

Cut = material removed from the ground (excavation).
Fill = material placed into the ground (embankment).
Net = the difference between the two.

Most earthwork projects involve both. You dig the high spots and move that material into the low spots to create a level surface. When the volumes balance, you don't need to import or export material — the cheapest scenario.

The Three States of Soil (This Is What Most People Miss)

Every cubic yard of dirt exists in three states depending on where it is in the process:

1. Bank Cubic Yards (BCY)

Soil in its natural, undisturbed state in the ground. Bank is tight, compressed by its own weight. This is what your survey measures before you touch it.

2. Loose Cubic Yards (LCY)

Soil after you've excavated it. When you dig dirt out, air gets introduced between particles. The volume expands. A cubic yard of bank dirt becomes 1.2 to 1.5 cubic yards of loose dirt once it's on a truck.

3. Compacted Cubic Yards (CCY)

Soil after it's been placed as fill and compacted. Compaction squeezes out air and packs the material tighter than even its original state. A cubic yard of bank dirt becomes about 0.85 to 0.95 cubic yards of compacted fill.

Why this matters (the $10,000 mistake):
Say you need 1,000 CCY of fill. A new contractor thinks: "Okay, I need 1,000 yards." Wrong. To get 1,000 CCY of compacted fill, you actually need about 1,200 BCY in the ground (material compresses) — and on the truck, that's about 1,500 LCY of loose material being hauled. If you ordered 1,000 yards, you're 500 yards short. That's 50 extra truck loads.

The Basic Formula

For uniform sites (building pads, parking lots):

Volume = Length × Width × Depth
Cubic Yards = (L × W × D) ÷ 27

Example: Building pad 60 feet long × 40 feet wide × 2 feet deep

Volume = 60 × 40 × 2 = 4,800 cubic feet
Cubic Yards = 4,800 ÷ 27 = 178 BCY

Swell Factor — How Much Bigger Dirt Gets

When you dig material out, it expands. The amount depends on the material:

Material Swell Factor Meaning
Gravel 8–12% 100 BCY = 108–112 LCY
Sand (dry) 10–15% 100 BCY = 110–115 LCY
Common earth / loam 20–25% 100 BCY = 120–125 LCY
Clay (moist) 25–30% 100 BCY = 125–130 LCY
Rock (blasted) 35–50% 100 BCY = 135–150 LCY

How to apply swell factor

Loose Volume = Bank Volume × (1 + Swell %)

Example with clay (28% swell):
LCY = 500 × 1.28 = 640 LCY

You're hauling 640 cubic yards of loose material, not 500. If your truck capacity is 12 LCY, that's 53 truck loads — not 42.

Shrink Factor — How Much Fill Gets Smaller

When you place dirt as fill and compact it, it compresses smaller than its original bank volume:

Material Shrink Factor Meaning
Gravel 5–8% 100 BCY = 92–95 CCY
Sand 5–10% 100 BCY = 90–95 CCY
Common earth 10–15% 100 BCY = 85–90 CCY
Clay 15–25% 100 BCY = 75–85 CCY
Bank Volume = Compacted Volume ÷ (1 − Shrink %)

Example: Need 1,000 CCY with 12% shrink
Bank Volume = 1,000 ÷ 0.88 = 1,136 BCY

Real Jobsite Example

The job: Cut a driveway through a hillside. 150 feet long × 16 feet wide × 3 feet deep average. Clay with rock (28% swell). Truck capacity: 12 LCY.

Step 1 — Bank volume:

Volume = 150 × 16 × 3 ÷ 27 = 267 BCY

Step 2 — Loose volume (swell):

LCY = 267 × 1.28 = 342 LCY

Step 3 — Truck loads:

Loads = 342 ÷ 12 = 28.5 loads → 29 loads

Step 4 — Haul time (30-min cycle per truck):

Total = 29 × 30 min = 870 min = 14.5 hours

With one truck, that's two shifts. With three trucks, it's a 5-hour operation.

Common Mistakes (And How to Avoid Them)

Using Dirt Calculator

The Dirt Calculator Cut & Fill tool eliminates manual errors. It:

Typical workflow: Pull out phone → open Dirt Calculator (installed as app) → enter length, width, depth → pick material → read off BCY, LCY, CCY, truck loads, weight — all at once. No cell signal needed.

Studying for a heavy equipment test? Cut and fill math is on every IUOE aptitude test, Red Seal exam, and NCCER certification. Dirt School's study guides include worked cut/fill problems with full answer keys.

Free Cut & Fill Calculator — works offline, all three volume states, truck loads included
IUOE Study Guide — $9.99, includes 60-question practice test with cut/fill problems
Red Seal Study Guide — $9.99, full earthwork coverage

Get the Free Cram Sheet

Master the formulas, definitions, and quick-reference guides used on every jobsite. Free 10-minute cram sheet + email updates.

✓ Instant PDF download | ✓ No spam | ✓ Used by 1,000+ operators