Excavation and Backfill Volume
ConvertEverything runs locally in your browser — nothing is uploaded
Enter the pit dimensions and the two conversion factors to get the excavated volume, the loose volume once dug, the backfill needed and the amount to haul away. The whole point is that three volumes are not one volume. Getting earthwork wrong comes down to “a cubic metre of soil” meaning three different things that can differ by 30%: · Bank (in situ) — the volume before the soil is touched. Quantities are usually measured on this. · Loose — the volume once dug and piled. Disturbed soil expands, typically ×1.3 for ordinary soil. How many truckloads to remove 100 m³ is a loose-volume question; using the bank figure under-orders by a third. · Compacted — the volume after backfilling and compaction, which is slightly smaller than bank (about ×0.87, since compaction is denser than the original). So backfilling the same pit needs more loose soil than the pit’s own volume. ⚠️ All three factors vary with soil type and local standards (sand, clay and rock differ, and so do regional schedules), so they are adjustable here and the value used is echoed back — a hard-coded constant would be dangerous in a quotation. ⚠️ This is the net volume of a vertical excavation — no side slopes, working space or shoring, because those follow from the ground conditions and the method, not from a few numbers.
Features
- ⚠️ Lists bank, loose and compacted separately — giving one “earthwork volume” is the classic error
- Shows the loose soil needed for backfill (both conversions applied)
- Shows the volume to haul away, and says so plainly when the site has enough
- Both factors are adjustable and echoed back in the result
- Accounts for the portion that is not backfilled (taken by foundations and services)
- Computed locally
How to use
- Enter the pit length, width and depth
- Enter the portion that will be backfilled (the rest is taken by foundations and services)
- Adjust the two factors for the soil and the local schedule
- The three volumes and the haul-off quantity appear immediately
FAQ
- How do bank, loose and compacted actually convert?
- The three are linked by two factors: loose = bank × 1.3 (soil expands when dug) and compacted = bank × 0.87 (compaction is denser than the original). From those, backfilling 1 m³ compacted needs 1 ÷ 0.87 × 1.3 ≈ 1.49 m³ loose. So backfilling a 60 m³ pit needs about 90 m³ of loose soil — far more than the pit’s volume, and ordering by pit volume is the usual way to come up short. Note that these factors vary with soil type and regional schedules; sand and clay differ noticeably, which is why they are editable.
- Why are side slopes and working space excluded?
- Because they follow from the ground conditions and the construction method, not from a few numbers. A real excavation adds side slopes (at a rate set by the soil), working space (room to build formwork or masonry), and shoring where used. What is given here is the net volume of a vertical excavation — the base figure every later calculation builds on, but not a quantity you can send out for pricing. For a tender, add those two items per your local schedule.
Related tools
Renovation Materials Calculator
ConvertWork out how much to buy from the area: paint by coverage and coats, tiles by size, flooring and wallpaper by pack or roll, all with a waste allowance.
Unit Price Comparison
ConvertList a few “name price quantity” lines to get each unit price, sorted cheapest first, with the best value marked and the rest shown as a percentage.
Timestamp Converter
ConvertConvert Unix timestamps into dates and back, telling seconds, milliseconds, microseconds and nanoseconds apart, with Windows FILETIME and decimals.
Date Calculator
ConvertCount the days, weeks or months between two dates, or shift a date by any of those. Dates can be picked from a calendar or pasted in — nothing is uploaded.
Number Base Converter
ConvertConvert numbers between binary, octal, decimal, hex, base 36 and base 64, with long IDs converted digit for digit. Runs in your browser.
Cron Parser
ConvertExplain a cron expression field by field and list the next and previous run times, saying plainly when a schedule can never fire.