Digging a hole produces more dirt than the hole holds. That sounds like a riddle, but it is the single fact that decides whether a small excavation job goes smoothly or ends with a pile in the driveway that nobody planned for.
Swell — the number nobody accounts for
Soil in the ground is compacted by everything above it and by time. Once you dig it out, it breaks up and traps air, and the loose volume is larger than the hole it came from.
For ordinary topsoil and loam, figure fifteen to twenty-five percent. For clay, twenty to thirty. For rock that has been broken, it can exceed fifty percent.
So a hole measuring ten cubic yards produces roughly twelve cubic yards of loose material to move. If you are hauling it away, that is the number that matters, not the hole volume. Set the waste field to your swell percentage and the calculator will carry it through.
Weight is what limits you, not volume
Damp earth runs around 2,200 pounds per cubic yard. Wet clay can pass 2,700. A cubic yard of soil looks like a small pile and weighs more than a ton.
That is why a half-ton pickup holds well under half a cubic yard of soil before it is over its payload, and why a full-size trailer fills up on weight long before it fills up on space.
The calculator reports the weight and the loads for this reason. Volume tells you how big the pile is; weight tells you how many trips it is.
Keeping the topsoil separate
The top six to twelve inches is the layer that grows things. Everything below it is subsoil and mostly worthless for planting.
Digging both into one pile destroys the topsoil, and then people buy topsoil back at the end of the job. Strip the top layer to one side before the main dig and it goes back on at the end for nothing.
Backfill does not use all of it
If you are backfilling around a foundation or a footing, you will not put back everything you took out — the structure now occupies part of that space, and the backfill has to be compacted in lifts rather than dumped.
Work out the backfill volume as the hole volume minus whatever you built in it, and plan to haul the difference. Compacting in six to eight inch lifts is what stops the ground beside a foundation from sinking two years later.
Before the shovel goes in
Call the national utility locate service before any dig deeper than a few inches. It is free, it is required almost everywhere, and gas and fibre lines run shallower than people expect.
That call takes a few days to schedule, so it comes before the excavator booking, not after.