Gravel calculator
Work out how much gravel you need to fill an area to a given depth, in cubic metres, tonnes and bulk bags.
Volume required-
Approximate weight-
Bulk bags (850kg)-
If filling IBRAN grids-
Grid cells hold roughly 60% of the equivalent open volume, because the cell walls take up the rest. This figure already allows for that, plus a 10mm blinding layer over the top.
For a gravel surface over grids, fill the cells level and add no more than a 5-10mm blinding. Anything deeper is unconfined stone, and unconfined stone migrates.
These figures are a guide for ordering. Site conditions, compaction and wastage vary, so check against your own measurements before placing a large order.