Compaction & waste buffer
Why add 10% extra fill dirt or gravel? How compaction and waste buffers work when ordering bulk material.
When you calculate raw cubic yards from length × width × depth, that number is the geometric volume. On a real job you usually order more — because material settles under compaction, some spills, and grade is never perfectly even.
A practical starting range
HowManyLoads defaults sit roughly in the 8–12% band as a planning starting point — not a lab test or supplier spec. Fill dirt and road base often lean toward the higher end; mulch may need less “compaction” but still benefits from a small waste cushion.
How the calculator applies it
order yards = raw yards × (1 + buffer%). Tune the slider for moisture, required compaction, and what your yard recommends. Then convert order yards to tons and truckloads.
Open fill dirt calculator Truck sizes
FAQ
Is 10% always enough?
No. Some structural fills or wet materials need more; some cover jobs need less. Treat the buffer as a dial, not a rule.
Does buffer change tons?
Yes. Tons scale with order yards (after buffer) times planning density.