Crushed Stone Calculator
Find how much crushed stone you need for a driveway base, patio base or drainage trench. Enter the area and depth to get cubic yards and tons, with a waste allowance.
Crushed stone needed
Assumes ~1.5 tons per cubic yard. A 50 lb bag holds about 0.5 ft³.
How to calculate crushed stone
Crushed stone is estimated the same way as any bulk aggregate: find the area in square feet, multiply by the depth converted to feet (depth in inches ÷ 12) to get cubic feet, then divide by 27 for cubic yards. The formula is cubic yards = area (ft²) × depth (in) ÷ 12 ÷ 27. Because crushed stone is priced and delivered by weight, the calculator also converts the volume to tons using a default density of 1.5 US tons per cubic yard, a little denser than rounded gravel since angular, crushed fragments pack together more tightly.
Crushed stone vs gravel
Gravel is naturally rounded by water or weathering; crushed stone is mechanically broken at a quarry, giving it sharp, angular faces that interlock when compacted. That interlocking makes crushed stone the stronger choice for load-bearing bases under driveways, patios, sheds and retaining walls, while rounded gravel is often preferred for decorative surfaces and drainage where water needs to move freely. If your project is a decorative or drainage application rather than a structural base, the gravel calculator or river rock calculator may fit better.
Sizing a driveway or patio base
A typical compacted base under a driveway is 4 to 6 inches of crushed stone, often built in two lifts: a coarser #3 or #4 stone (1 to 2 inches) as the sub-base, compacted, then a finer #57 stone or 3/4 inch minus as the running surface. A patio or shed pad base is usually 3 to 4 inches. Enter each layer separately if your project uses more than one stone size, and add the totals together.
Waste and ordering
A 5 percent allowance is reasonable for crushed stone, since it compacts somewhat as it is spread and tamped, slightly reducing the finished depth versus the loose volume delivered. Order a little extra rather than running short mid-job, since a second small delivery often costs nearly as much as the original load. Once the base is down, size any slab on top with the concrete calculator or the paver surface with the paver calculator.