Grab lorry removing muck away spoil from a UK construction site

UK Grab Lorry Estimator

Muck Away & Soil
Swell Calculator.

Q: How do you calculate muck away volume?

To calculate muck away volume, you must first calculate the solid cubic volume of your excavation (Length × Width × Depth). Then, you multiply that solid volume by the specific 'swell factor' or 'bulking factor' of the soil type. For example, solid clay expands by roughly 30% when excavated, so 10m³ in the ground becomes 13m³ of loose muck away.

Q: What is the bulking factor of excavated clay?

In the UK, the bulking (or swell) factor for stiff excavated clay is typically between 20% and 30%. This means for every 1 cubic metre of solid clay dug out of the ground, you must plan to transport 1.2 to 1.3 cubic metres of loose spoil.

Q: How many cubic metres fit in a 16t grab lorry?

An 8-wheel 16-tonne grab lorry can legally carry 16,000kg of payload. Volumetrically, this usually equates to between 12 and 14 cubic metres of loose, excavated soil or hardcore, depending on the moisture content and specific density of the material.

Stop overbooking transport. Automatically translate compacted in-situ site measurements into true uncompacted loose volumes using UK-specific soil bulking factors.

Get Started Use the Live Calculator ›

Muck Away Tonnage & Load Estimator

1

Enter Excavation Dimensions

Input the solid length, width, and depth of the footprint you are digging out.
2

Select Spoil Classification

Choose between Topsoil, Clay, Chalk, or Mixed Hardcore. The algorithm applies the correct density and bulking expansion metrics.
3

Get Instant Lorry Counts

Instantly view the total loose tonnes generated and the exact number of standard 16-tonne grab lorries required to clear the site.

Save to Your Digital Site Log

Use the live muck away calculator below for free. To save this haulage calculation to your digital log and share it with site agents, upgrade to Premium today.

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Muck Away

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~1 Grabs

~6.24m³ loose / ~6.24t

Material Order

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~7.35t

~5.05m³ loose

🔒 Unlock

Displacement

0.245m³

1. Trench Geometry

Length (m)

Width (m)

Total Depth (m)

Ground / Spoil Type

2. Layer Build-Up (Free Version)

⬆ Ground Surface ⬆

🔒 Unlock Top Fill Setup

🔒 Top Fill (Auto-Depth)

0.00m

Main Fill

Layer Depth (m)

Compaction Status

Pipes

No pipes. Pure fill.

⬇ Trench Bottom ⬇

Materials Breakdown

10/20mm Pea Shingle

Compacted • 4.800m³ net space

~7.35t

~5.05m³ order (loose)

🔒

Save to Site Log (Pro)

Why Calculate Soil Bulking & Swell Factors?

Earthworks tracking errors destroy site margins. Underestimating your loose volumes leads to expensive, unbudgeted transport standing charges.

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Native Soil Swell Factors

Stiff clay bulks up by nearly 30% when excavated, whereas sharp sand expands by roughly 12%. DigFill applies the exact soil bulking factor based on the material, preventing dangerous miscalculations.

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Grab Lorry Load Capacities

A single mathematical error means an excavator sits idle waiting for a lorry. Our engine converts your loose m³ directly into 16T grab lorry load counts so you can book transport with confidence.

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Weight vs Volume Limits

A truck might 'look' half empty, but if it hits its maximum tonnage limit, it cannot legally take more. The muck away calculator cross-checks both volume and weight thresholds simultaneously.

FAQ

Common Muck Away Calculations

How do you calculate muck away volume? ▼

To calculate muck away volume, first measure the solid cubic capacity of your excavation pit (Length × Width × Depth). Then, multiply that solid volume by the 'swell factor' of the specific soil type. Heavy soils expand significantly once disturbed, meaning your final loose muck away volume will always be larger than your hole dimensions.

What is the bulking factor of excavated clay? ▼

In UK groundworks, the bulking (or swell) factor for stiff excavated clay ranges from 20% to 30%. This means for every 1m³ of solid clay dug out of the ground, you must account for 1.2m³ to 1.3m³ of loose material when booking grab lorries.

How many cubic metres fit in a 16t grab lorry? ▼

A standard 8-wheel grab lorry has a legal payload capacity of 16 tonnes. Depending on the density and moisture content of the soil, this typically equates to between 12m³ and 14m³ of loose spoil per load. Extremely wet or dense clay will max out the weight limit before the volumetric space is completely full.

Muck Away & Soil Swell Calculator.