Crushed stone splits into two families that do opposite jobs. Clean stone drains and does not compact. Dense-graded stone compacts hard and does not drain. Order the wrong one and the job fails in a way you will not see for a season. This works out both the size and the quantity.
Pick what the stone is for, and the size follows. Then enter the area and the finished compacted depth.
Works in metric and US imperial — you choose at the start and can switch at any time. Every figure this calculator uses is published with its source, and the result comes with a printable order sheet. No account, no email, and nothing you type leaves your browser.
Related: #57 stone calculator · Crusher run calculator · Gravel calculator
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Pick what the stone is for and the size follows; enter the area and the finished compacted depth. The calculator applies the right allowance for the family you chose — about 25% for dense-graded stone, 14% for clean — and converts to the tonnage your yard sells. The depth you type is the finished depth, so order the loose figure it returns and do not add a compaction allowance on top.
Clean stone drains and does not compact. Dense-graded stone compacts hard and does not drain. Order the wrong one and the job fails in a way that is expensive to undo — a patio base that will not hold level, or a drain that has silted solid. Dense-graded (crusher run, 3/4 minus) goes under anything that must stay put. Clean stone (#57, #67) goes anywhere water must move through.
In America, ASTM D448 and AASHTO M43 define the sieve envelopes, so the numbers are specifications rather than yard slang. #57 is 3/4 in nominal, clean, with 0–10% passing the #4 sieve. #8 is 3/8 in chips. Crusher run is not in that system at all — it is a dense-graded product sold under local names. Quote the number where one exists and you and the yard are describing the same stone.
Clean stone is washed and single-sized with the fines removed, so it drains freely and does not compact. Crusher run is dense-graded, meaning it contains everything from 3/4 in down to dust, so the fines lock together under a compactor and it does not drain. Use clean stone for drainage, dense-graded for anything that has to stay level.
Compact in layers of 75–100 mm (3–4 in) per pass with a domestic plate compactor. A 150 mm driveway base is two lifts. This matters more to whether the job lasts than the total depth does — a plate cannot compact through more than about 100 mm of loose material, so a single deep layer stays loose underneath.
For clean stone, good: the FHWA measured #57 between 95.4 and 108.7 lb/cu ft dry unit weight. For dense-graded stone, weaker, and we would rather say so — no universal figure exists, because maximum dry density depends on the source rock, and at least one state highway authority states as much. If your yard quotes a figure, use theirs.
Yes, and where stone is sold by weight a soaked stockpile delivers less material for the same tonnage. Ordering by volume avoids the problem where the yard allows it.