Shrink/Swell Calculator
Apply swell when material is excavated (bank to loose) and shrink when it is compacted (bank to compacted). Use it before ordering trucks or import fill.
Enter your values, then press Calculate.
How to calculate
Enter in-place bank cubic yards. Swell is typical 10–40% for soils (higher for riprap and rock). Shrink is the loss from bank to compacted in-place; 10–20% is common for many fills. Both may be zero if you only need one conversion.
Formula
Loose yd³ = bank yd³ × (1 + swell%/100). Compacted yd³ = bank yd³ × (1 − shrink%/100). Load factor = loose ÷ bank.
Common use cases
- Spoils haul volume
- Import fill after compaction
- Comparing cut vs fill
- Checking a geotech swell table
Worked example
Example: 100 bank, 25% swell, 10% shrink
1. Apply swell
100 × (1 + 25%) = 125 yd³
2. Apply shrink
100 × (1 − 10%) = 90 yd³
Related calculators
- Trench Spoils CalculatorConvert bank trench yards to loose spoils and truckloads using a swell factor.
- Truckload EstimatorConvert cubic yards into truckloads using a real truck capacity.
- Backfill CalculatorEstimate trench backfill cubic yards after subtracting pipe displacement.
- Trench Excavation CalculatorConvert trench length, width, and depth into cubic yards of excavation.
FAQ
Are swell and shrink applied together?
They answer different questions. Swell is for hauling excavated material. Shrink is for how much bank you need to end up with a compacted fill. Do not chain them into one mystery factor unless your geotech says to.
Where do the percentages come from?
Use the geotech report, borrow-pit history, or typical ranges for that soil. The calculator does not invent a factor from the soil name.
Disclaimer
These calculators are estimating tools for planning and field checks. They are not a substitute for approved plans, specifications, licensed professional engineering, or governing standards. Confirm densities, waste factors, and yields with your supplier and project documents.