Calculate backfill material needed after pipe installation with compaction factor and pipe displacement.
This backfill calculator determines how much material you need to order to refill a trench after pipe or conduit installation. It accounts for the volume occupied by the pipe and the compaction loss that occurs when loose material is placed and tamped.
The void volume is the space that needs to be filled with backfill material:
Loose backfill material compresses when placed in the trench and mechanically compacted. The compaction factor accounts for this volume reduction so you order enough material to fully fill the void:
Weight is calculated from the order volume multiplied by the soil's loose density (kg/m³). This helps determine delivery requirements and whether weight limits will be a factor for hauling.
Total trench length
Trench width
Trench depth from ground surface
Multiplier applied to void volume. Auto-filled from material, but can be overridden.
Used for weight estimation based on soil density
Order quantity accounts for 25% compaction loss during placement
Length x Width x Depth
Space to fill after pipe installation
Based on loose soil density
Order quantity exceeds void volume because loose material compacts during placement. The compaction factor of 1.25 accounts for this loss. Material type: Native Soil.