Estimate backfill volume in cubic yards for trenches and foundations. Enter length, width, and fill depth — includes swell and hauling factors.
Reviewed by Marcus Delaney, Licensed General Contractor · Last updated: May 2026
This backfill tool counts what goes back in the trench after the pipe is set—not the whole cut you exported. Plumbers and utility guys use it to order sand or select fill before the inspector shows up. Pair it with a trench cut takeoff so you're not double-paying haul trucks.
Same prism as export, but measure only the void you're filling:
Fill cu yd = Length × Width × Fill height ÷ 27
Buffer: Order = Fill × (1 + Buffer% ÷ 100)
Tons: Tons = Order yd × tons/yd — clean sand often plans near 1.3 t/yd loose.[1]
We set 1-in copper on a 52 ft run—trench stayed 15 in wide, but we only filled from top of sand bedding to grade, 20 in. That's 52 × 1.25 ft × 1.67 ft = 108 cu ft ÷ 27 = 4.0 cu yd sand. Eight percent buffer → 4.3 yd. At 1.3 t/yd ≈ 5.6 tons—one pickup load with bags to spare.
Fill height above bedding. Don't use full trench depth if pipe and bedding already ate the bottom. Measure crown to finish grade in the slot.
Sand vs flowable fill. Flowable fill prices per yard jump, but it finds voids under pipe. Sand needs careful lifts—volume still comes from the prism.[1]
Compaction lifts. IBC-driven projects often want 6–8 in lifts on granular backfill. Loose yards order more than compacted in-place yards.
Pavement zones. Under sidewalk, you'll cap with road base after sand—order base separately.
Reusing spoil. If geotech lets you reuse trench spoil, subtract what you put back from import—don't order sand you don't need.
Only if the engineer spec allows it. Flowable fill costs more and needs cure time—sand lifts still win on tight residential water services.
Enter fill length, width, and height above bedding. The tool gives yards, then tons from the weight you pick.
Usually yes—in lifts. Don't run a big roller over shallow PE gas; hand tampers win near pipe.
Trench tool is the full hole. This is only what returns above pipe. Run the trench calculator first if you need export.
Only when soils report says so. Most water lines want sand or select granular—clay settlement bites you later.
Backfill yards change with lift compaction, moisture, and whether you're using sand or flowable fill—confirm with your material ticket before you buy.