Cubic Metres to Tonnes Calculator 2026

Example 1: Concrete Slab

Project: 10m × 8m × 0.15m concrete slab

Volume: 10 × 8 × 0.15 = 12 m³

Density: 2400 kg/m³ (standard concrete)

Weight: 12 × 2400 = 28,800 kg

Weight in tonnes: 28,800 ÷ 1000 = 28.8 tonnes

Example 2: Driveway Gravel

Project: 20m × 3m × 0.1m gravel driveway

Volume: 20 × 3 × 0.1 = 6 m³

Density: 1800 kg/m³ (gravel)

Weight: 6 × 1800 = 10,800 kg

Weight in tonnes: 10,800 ÷ 1000 = 10.8 tonnes

Example 3: Topsoil Fill

Project: 15m × 10m × 0.3m garden area

Volume: 15 × 10 × 0.3 = 45 m³

Density: 1400 kg/m³ (topsoil)

Weight: 45 × 1400 = 63,000 kg

Weight in tonnes: 63,000 ÷ 1000 = 63 tonnes

Example 4: MOT Type 1 Base

Project: 25m × 4m × 0.2m road base

Volume: 25 × 4 × 0.2 = 20 m³

Density: 1500 kg/m³ (Type 1 MOT)

Weight: 20 × 1500 = 30,000 kg

Weight in tonnes: 30,000 ÷ 1000 = 30 tonnes

Material Ordering

Challenge: Suppliers quote by weight (tonnes) but site requires volume calculations

Solution: Convert calculated volume to tonnes for accurate ordering

Benefit: Prevents over-ordering and minimizes waste costs

Example: Order 24 tonnes concrete for 10m³ requirement

Vehicle Loading

Challenge: Ensure vehicles aren't overloaded (legal limit 44 tonnes gross)

Solution: Calculate material weight to comply with DVSA regulations

Benefit: Avoid fines, maintain safety, plan delivery logistics

Example: 8-tonne tipper can carry ~3.5m³ concrete safely

Cost Estimation

Challenge: Material suppliers price by tonne, project specs in m³

Solution: Convert volume to weight for accurate budget planning

Benefit: Precise quotations, better project financial control

Example: 50m³ topsoil = 70 tonnes × £25/t = £1,750

Waste Removal

Challenge: Skip hire charged by size, but need weight calculation

Solution: Ensure waste weight doesn't exceed skip capacity

Benefit: Choose correct skip size, avoid overweight charges

Example: 6m³ concrete waste = 14.4t (requires 16t skip minimum)

Foundation Design

Challenge: Calculate dead load for structural calculations

Solution: Convert structural volumes to accurate weight loads

Benefit: Proper foundation sizing, structural safety compliance

Example: 5m³ floor slab = 12 tonnes dead load

Site Access Planning

Challenge: Weak ground or restricted access limits vehicle weight

Solution: Calculate number of smaller loads required

Benefit: Prevents site damage, maintains schedule

Example: 40t material needs 5× 8t loads for narrow access

Moisture Content

Impact: Water adds significant weight to absorbent materials

Example: Dry sand 1600 kg/m³ vs wet sand 1900 kg/m³

Variation: Up to 20% density increase when saturated

Consideration: Store materials covered, adjust for weather conditions

Compaction Level

Impact: Compacted materials are denser than loose state

Example: Loose topsoil 1200 kg/m³ vs compacted 1600 kg/m³

Variation: 15-30% density difference post-compaction

Consideration: Calculate for in-place compacted density

Particle Size Distribution

Impact: Well-graded materials pack denser than single-size

Example: Mixed ballast denser than single-size aggregate

Variation: 10-15% density difference

Consideration: Specify grading requirements when ordering

Material Source & Type

Impact: Regional variations in rock/soil mineral content

Example: Limestone aggregate lighter than granite aggregate

Variation: 10-25% between material types

Consideration: Use local supplier density specifications

Temperature Effects

Impact: Materials expand/contract with temperature change

Example: Asphalt density varies with temperature

Variation: Generally minimal (1-3%) for aggregates

Consideration: More significant for asphaltic materials

Organic Content

Impact: Organic matter reduces overall density

Example: Organic-rich topsoil lighter than mineral soil

Variation: Can reduce density by 20-40%

Consideration: Important for landscaping materials