Muck Away & Grab Lorry Calculator

Muck Away Calculator

Calculate bulk excavation volume (with swell factor), weight in tonnes, number of grab lorry loads, skip requirements and indicative disposal costs — instantly.

Last reviewed 15 May 2026
Metric & Imperial
9 Soil Types
Swell Factor Included
Cost Estimate Included
Rule of thumb: A 10-tonne grab lorry carries approximately 6 m³ of bulked clay or 7 m³ of sandy soil after swell. Clay swells 25% when excavated — 4 m³ in the ground becomes 5 m³ in the lorry. Inert disposal runs £28–£45 per tonne in 2026 (London and South East higher).
Excavation Details
Enter your dimensions and select your soil type
Unit System
Excavation Style
Excavation Dimensions
m
Please enter a valid length
m
Please enter a valid width
mm
Enter depth in millimetres. A standard foundation strip is typically 600–900mm. Please enter a valid depth

Soil type affects both density (weight) and swell factor (how much it expands when excavated).

Disposal Options
The best grab lorry and skip size are automatically selected based on your project weight and volume. Both options are shown in results so you can compare costs.
%

Add 10–15% to cover measurement inaccuracies and loading variance. Industry standard is 10%.

Site Conditions

Required for 8-wheel grab lorries (~3.5m wide, ~6m arm height).

Adds typical council permit fee (~£75) to skip estimate.

Results are indicative estimates. Always verify quantities on-site and get multiple quotes for disposal.

How It Works

The Muck Away Calculation Method

Understanding how excavated volume is calculated helps you get more practical estimates and avoid under-ordering lorry loads.

1
Calculate In-Situ Volume

Length × Width × Depth gives you the in-situ volume — the amount of space the soil occupies in the ground in its natural, compacted state.

2
Apply the Swell Factor

When soil is excavated, it expands (bulks up). Clay swells by ~25%, sand by ~12%, rock by ~50%. This multiplier converts in-situ volume to bulk volume — what actually fits in your lorry or skip.

3
Calculate Weight

Multiply in-situ volume by the soil's bulk density to get weight in tonnes. This is used for lorry load calculations (lorries are rated by weight, not volume) and disposal cost estimates.

4
Add Contingency & Divide by Capacity

A 10% contingency is added to account for measurement inaccuracies and over-dig. The total is then divided by your chosen lorry's maximum payload (in tonnes) and rounded up to give the final number of loads.

Soil Type Reference Data
Used in our calculations
Soil Type Density (t/m³) Swell Factor Bulking %

Professional Guide

Spoil Removal & Disposal — What You Need to Know

Removing waste from a site is one of the most underestimated costs in UK construction. Whether you're digging foundations for an extension or clearing a garden for a new patio, understanding the volume of spoil before you book disposal is critical for your budget.

Muck Away Costs by Disposal Type

Muck away is a highly local service. Prices fluctuate based on your distance from a waste transfer station, regional tip fees, and whether the material is classified as inert. London and the South East typically attract significantly higher rates than the Midlands or North.

Inert Muck (clean soil, stone, concrete)
Standard trade rates: £28 – £45 per tonne. Clean material attracts the lowest tip fees and is usually accepted as Type A fill. Per grab load: roughly £250 – £450.
Non-Hazardous / Mixed Waste
High organic content, mixed demolition waste or contaminated material. Expect to pay a premium of £100+ per load over inert rates. Requires correct EWC classification.

Skip Sizes Explained

A “Yard” in skip terms refers to a cubic yard (0.76 m³). Below are standard UK trade capacities with their metric equivalents. Note that heavy materials like soil impose weight limits before volume is reached.

Skip Size Capacity (m³) Best For Notes
4 Yard Mini Skip ~3.1 m³ Small garden clearance Light waste only
6 Yard Midi Skip ~4.6 m³ Soil & rubble Heavy waste; check weight limit
8 Yard Builder Skip ~6.1 m³ Driveways, patios, foundations Most common trade skip
10 Yard Large Skip ~7.6 m³ Commercial clearance Heavy waste weight limit applies
12 Yard Maxi Skip ~9.2 m³ Light house clearance Not suitable for soil/rubble — lorry cannot lift when full of heavy material
14 Yard Roll-on Skip ~10.7 m³ Large commercial sites Requires adequate site access

Grab Lorry vs Skip — UK Vehicle Capacities

For larger excavations, a grab lorry is almost always faster and more cost-effective than skips. One standard 8-wheel grab lorry carries roughly the equivalent of 2.5–3 builders’ skips in a single trip.

Vehicle Max Weight Volume (m³) Skip Equiv.
4-Wheel Grab 8–10 T 5–6 m³ ~1 Builder’s Skip
6-Wheel Grab 12–13 T 8–10 m³ ~2 Builder’s Skips
8-Wheel Grab (HGV) 14–16 T 10–12 m³ ~3 Builder’s Skips
Tipper Lorry Up to 20 T 14–16 m³ ~4 Builder’s Skips

Note: actual payload is whichever limit (weight or volume) is reached first. For wet clay or concrete, the weight limit is usually the binding constraint.

Wet Muck & Geological Variance — Not all soil is equal. Heavy wet clay (High Plasticity / HP) can have a density of 2.0–2.2 t/m³ when saturated, compared to 1.3–1.5 t/m³ for dry sandy topsoil. This means a grab lorry’s weight limit is hit much faster with wet material, effectively reducing the usable volume per trip. Our calculator uses in-situ density per soil type — always select the closest match.

Regulation & Compliance

Disposing of construction waste is legally regulated in the UK. As a site owner or contractor, you are responsible for ensuring your waste is removed by a licensed carrier and properly documented.

Digital Waste Tracking (DWT) — From 2026
New UK regulations require all construction and demolition waste to be tracked digitally. This replaces paper-based Waste Transfer Notes (WTNs). Your waste carrier must use a Defra-compliant digital system. When estimating volumes for digital filings, use the following EWC (European Waste Catalogue) codes:
  • 17 05 04 — Soil and stones (Inert, clean material)
  • 17 01 07 — Mixed concrete, bricks, tiles and ceramics
  • 17 09 04 — Mixed construction and demolition wastes
Waste Carrier’s Licence — Always confirm your waste contractor holds a valid licence before they remove material from site. You can verify this on the Environment Agency’s website. If unlicensed waste is fly-tipped using your material, you may be held liable.
Waste Classification — Not all excavated material is “inert”. Soil containing construction fill, organic matter, hydrocarbons or any contamination must be correctly classified.
  • Inert Waste: Uncontaminated soil, stone, brick, tiles and concrete — lowest disposal cost
  • Hazardous Waste: Asbestos-contaminated material, petroleum-affected soil, and certain made ground — requires specialist licensed disposal
GOV.UK — Waste Duty of Care Check a Registered Waste Carrier

FAQ

Frequently Asked Questions

Swell factor (also called bulking factor) is the ratio by which soil increases in volume when it is excavated from its compacted, in-situ state. Clay typically swells by 25%, meaning 1 cubic metre of clay in the ground becomes 1.25 cubic metres when loosened and loaded onto a lorry. Ignoring swell factor often leads to underestimating lorry loads and disposal costs.
Disposal is calculated on the bulk (loose) volume and weight of material after excavation. The key steps are: (1) calculate in-situ volume (L × W × D), (2) apply the swell factor for your soil type to get bulk volume, (3) divide bulk volume by lorry capacity to get number of loads, (4) multiply in-situ weight by disposal cost per tonne for an indicative price.
Muck away costs in the UK typically range from £28 to £72 per tonne in 2025, depending on material type, location, access and current landfill tax rates. Clean, uncontaminated soil is cheaper to dispose of than mixed or contaminated waste. Urban areas with restricted access attract higher costs. Always obtain multiple quotes and ask for a confirmation of the tipping site.
Grab lorries come in 8-tonne, 10-tonne and 14-tonne (HGV) sizes. For most domestic projects, a 10-tonne grab lorry is the standard choice, offering good capacity with access to most residential streets. For large commercial excavations, 14-tonne HGV lorries are more economical per load. Always check access restrictions — road width, turning circles and overhead lines — before specifying a vehicle type.
Grab lorries are generally more cost-effective for larger volumes of soil (over 5 m³) as they have higher capacities and can load directly from the excavation without manual handling. Skips are better for smaller volumes, mixed waste, or where space is limited and the lorry cannot access the site. Our calculator shows both options so you can compare and choose the best approach for your project.
Yes. In the UK, placing a skip on a public highway requires a permit from your local council. The skip hire company will usually arrange this on your behalf, but you should confirm this when booking. Permits are not required for skips placed entirely on private land (e.g. your driveway). Costs and lead times vary by council.
The weight of 1 m³ of soil depends heavily on type and moisture content. Dry sandy topsoil weighs approximately 1.35 t/m³, standard clay 1.85 t/m³, and saturated clay or concrete can reach 2.2–2.3 t/m³. Our calculator uses in-situ bulk densities per soil type, so always select the closest match for the most practical weight estimate.
A standard 10-tonne grab lorry carries approximately 6 m³ of loose (bulked) material, which is roughly 7.8 cubic yards. An 14-tonne HGV grab can carry up to 8.5 m³ (about 11 cubic yards). For context, one standard 8-yard builder’s skip holds approximately 6.1 m³, so a 10-tonne grab lorry is broadly equivalent to one skip per trip in volume terms — but significantly faster to load.
Yes, but wet clay significantly reduces usable capacity. Saturated clay has a density of up to 2.0–2.2 t/m³, meaning a 10-tonne lorry can only carry roughly 4.5–5 m³ before its weight limit is reached — compared to 6–7 m³ with dry material. Always select “Clay” in our calculator (rather than topsoil) to ensure you get practical load counts when dealing with wet, heavy ground conditions.
From 2026, new UK regulations require all construction and demolition waste to be tracked digitally, replacing paper Waste Transfer Notes (WTNs). As a site owner or principal contractor, you must ensure your waste carrier uses a Defra-compliant digital tracking system. The key EWC codes for excavation waste are: 17 05 04 (inert soil and stones), 17 01 07 (mixed concrete, bricks and tiles) and 17 09 04 (mixed C&D wastes). Our calculator helps you estimate the volumes needed for these digital filings.

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