Drainage & Earthworks
Soil Compaction Calculator
Adjusts bulk material volume for compaction factor after laying
Updated June 26, 2026 · Live
What this tool does
Adjusts bulk material volume for compaction factor after laying.
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How the compaction factor calculator works
Adjusts bulk material volume for compaction factor after laying. The calculator takes a loose volume and the material, divides by the material's bulking factor, and returns the settled in-situ volume with the shrinkage that goes with it. Every figure is an estimate — site conditions always move the final number.
Typical Canadian drainage and earthworks wastage
Excavated soil typically bulks up by around 15–35% when lifted, depending on the material, so dumpster capacity fills faster than the in-situ volume suggests. A rough 1.25× allowance is common for muck-away dumpster filling, which is a separate figure from the per-material bulking factor this tool divides by. These are trade-typical values rather than a site test, so they shift with moisture, layer depth and compaction effort.
What this tool does not do
It does not replace a professional quote, factor regional pricing, assess structural adequacy, or confirm National Building Code (NBC) compliance. Those remain the responsibility of a suitably qualified designer, surveyor, or your building inspector.
On-site considerations for compaction factor
Excavations over 1.2 m deep typically need shoring or battered sides, and HSE guidance on trench collapse applies. Buried services are located with a CAT scanner before digging.
the National Building Code (NBC) and compliance
Foul and surface water drainage to a public sewer is governed by the National Building Code and Sewers for Adoption. Dry wells need a permeability test (BRE 365) to size correctly. A pre-application enquiry to the municipality can give early clarity, which tends to be less costly than retrospective correction.
Before you order
Plastic drainage pipe is commonly supplied in standard 3 m or 6 m lengths with integral seal joints, and cutting short lengths on site wastes material and fittings. Cross-checking the calculator’s output against a supplier quote helps catch differences in pricing assumptions — a quote listing exact product specifications (grade, finish, batch number) with confirmed delivery timescales is easier to reconcile against a programme.
Adjusting the defaults
Every input in this calculator is editable. Enter your own loose volume and choose the material — the output recalculates instantly. If the default does not match your job, your own numbers always override it.
Using this compaction factor calculator alongside other BuildMetricLab tools
This calculator works best as part of a planning workflow. Pair the quantity with our project contingency, labour-hours, and material-cost calculators to build a complete estimate before you pick up the phone to a supplier. All BuildMetricLab tools run entirely in your browser — no sign-up, no data sent anywhere, and every formula is shown on-page so you can audit the maths.
Sources & methodology
Adjusts bulk material volume for compaction factor after laying. Every result is calculated from the values you enter, and all inputs are editable.
Frequently asked questions
Are compaction factor calculator results accurate enough to order materials?
Use them as a starting estimate only. Verifying the final quantity with your supplier or contractor before ordering is good practice — site conditions, wastage and cut-offs all affect the true figure.
Which material should I choose?
The material you choose sets the bulking factor the tool divides by, so the closest match to what is being placed gives the best estimate. Clay and chalk bulk most (about 1.35–1.40), loam and topsoil sit around 1.25, sand is lower at 1.15, and rock is highest at 1.65. These are trade-typical values, so material that is wetter, drier or more broken than usual settles differently.
Does this replace professional advice?
No. This tool is a planning estimator. For works that affect structure, the National Building Code (NBC), property-line or shared-wall, gas, electrics, drainage to a sewer, or similar, consult a suitably qualified professional.
Can I change the bulking factor directly?
Not directly — the factor is set by the material you choose from the drop-down, using trade-typical values. The closest material to the figure you want gives the nearest result, and the tool shows the factor it applied next to the result, so the conversion stays auditable.
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