🔨

Compacted Fill Calculator

Find how much loose fill (earth, clay, sand, gravel or crushed stone base) to order for a compacted layer: compaction factor, loose m³ or yd³, tonnes and truckloads.

Units

Area to fill (m² or ft²)

Compacted depth (cm or inches)

Fill material

Truck capacity (m³ or yd³)

Loading calculator…

How it works

compacted volume = area × depth · loose volume = compacted volume × compaction factor · weight = loose volume × loose density · truckloads = loose volume ÷ truck capacity (rounded up)

Fill is bought and hauled loose but placed and rolled to a denser state, so more loose material is needed than the finished compacted volume. The compaction (shrink) factor combines the swell of excavated material with the shrinkage when it is compacted to about 95% Proctor: about 1.25 for common earth, 1.30 for clay and crushed stone base, 1.20 for gravel and 1.15 for clean sand. Weight uses typical loose densities from equipment handbooks (1.5–1.65 t/m³). Compact in lifts of 15–20 cm, at the right moisture content, for the factor to hold.

Worked example

Filling 100 m² to a compacted depth of 20 cm with common earth: compacted volume = 100 × 0.20 = 20 m³; loose to order = 20 × 1.25 = 25.00 m³, about 25 × 1.5 = 37.5 t, which is 25 ÷ 7 = 3.6 → 4 truckloads of 7 m³.

Sources: Caterpillar Performance Handbook — material densities and load factors · FHWA — Soils and Foundations Reference Manual (compaction)

Frequently asked questions

How much more fill do I need for compaction?

Typically 15–30% more loose material than the finished volume: about 25% for earth, 30% for clay and crushed base, 20% for gravel and 15% for sand. Wet or poorly graded material can need more.

What is the difference between swell and shrinkage?

Swell is the growth in volume when soil is dug from the ground (bank) and loosened; shrinkage is the loss in volume when it is compacted below its bank volume. The compaction factor here goes straight from the loose material you order to the compacted result.

How thick should each compacted layer be?

Usually 15–20 cm (6–8 in) loose per lift for a plate compactor, up to 30 cm for a heavy roller. Thicker lifts do not compact properly at the bottom.

How many tonnes is a cubic metre of fill?

Loose earth weighs about 1.5 t/m³, sand and gravel about 1.6 t/m³ and clay about 1.65 t/m³. Once compacted, the same material is around 1.8–2.1 t/m³.

Related calculators

Excavation Calculator

Calculate the bank and loose (hauled) volume of a dig in cubic yards, plus the number of truckloads, from length, width, depth and swell.

Cut and Fill Calculator

Balance a grading job: cut and fill volumes from zone areas and average depths or from a grid of cut/fill depths (borrow-pit method), with soil swell and compaction shrinkage, bank, loose and compacted volumes, the soil to haul off or import, truckloads, haul cost and the grade change that balances the site.

Gravel Calculator

Gravel for a driveway, path or base: cubic yards, tons and bags for rectangles, circles, triangles, rings or a list of areas, with stone-type densities, compaction allowance, bulk vs bag cost and truckloads.

Topsoil Calculator

Calculate cubic yards and tons of topsoil for a lawn or bed from length, width and depth.

Gravel Base Depth Calculator

Calculate the gravel for a compacted base in cubic yards and tons from the area and how deep you want the base.

This calculator is for educational purposes. Double-check important results before acting on them.