Waste Tonnage Calculator — How Much Does My Construction Waste Weigh?

It varies significantly by material type. Concrete rubble is the heaviest at approximately 2,200 kg/m³, followed by brick rubble at 1,800 kg/m³, soil at 1,500 kg/m³, mixed waste at 1,000 kg/m³, plasterboard at 800 kg/m³, and timber at up to 500 kg/m³. These are indicative waste-form bulk densities (based on WRAP and Environment Agency conversion factors) and vary with compaction, moisture and material mix — treat them as estimates and confirm with your waste carrier. Note: loose waste timber (offcuts with air gaps) is much lighter than solid timber, often only 130–400 kg/m³, so the 500 kg/m³ figure is a conservative upper bound; and mixed/general waste in particular ranges roughly 0.3–1.0 t/m³.

Landfill Tax is a UK government tax on waste sent to landfill, designed to encourage recycling and waste reduction. There are two rates: the standard rate of £130.75 per tonne for active (non-inert) waste like plasterboard, timber, plastic and mixed waste; and the lower rate of £8.65 per tonne for inert waste like brick, concrete, stone and uncontaminated soil. These rates apply from 1 April 2026.

Plasterboard (gypsum) must be separated because when it decomposes in landfill alongside biodegradable waste, it produces hydrogen sulphide gas which is toxic and has a strong rotten egg smell. Under the Environmental Permitting Regulations, plasterboard must be disposed of in a dedicated cell at landfill that does not contain biodegradable waste, or sent to a plasterboard recycling facility.

Inert waste attracts the lower landfill tax rate of £8.65 per tonne (HMRC, from 1 April 2026). This includes: brick, concrete, stone, tiles, ceramics, glass, uncontaminated soil and subsoil, rock, gravel, sand, clay, and calcium sulphate (when in a cell with only inert waste). These materials do not decompose, burn, or react chemically in landfill.

Yes, several strategies can reduce costs: (1) Separate inert waste (brick, concrete, soil) from active waste to benefit from the lower landfill tax rate. (2) Recycle plasterboard through a dedicated service. (3) Use timber for biomass/fuel rather than landfill. (4) Crush brick and concrete on site for reuse as hardcore. (5) Use a waste transfer station rather than direct landfill for sorting. (6) Minimise waste through accurate ordering and careful handling.

Yes — and for heavy waste the weight limit usually matters more. UK skip operators rate each size by both volume and weight: a 2-yard mini holds roughly 2 tonnes, a 4-yard midi about 4 tonnes, a 6-yard about 6 tonnes and an 8-yard about 8 tonnes. Dense waste such as rubble, concrete and soil hits the weight limit long before the skip looks full, so a skip that is the right volume can still be over its weight allowance. For that reason rubble and hardcore are normally restricted to 8-yard skips or smaller — a fully loaded larger skip would be too heavy for the collection lorry to lift safely or legally. This calculator gives you the volume-based skip size and flags a warning when your calculated tonnage exceeds that skip’s typical weight allowance, but always confirm the exact limit with your waste carrier.