About Gravel & Aggregate Calculator
The gravel and aggregate calculator answers "how much gravel do I need" for driveways, paths, patios, drainage layers, and base courses. Enter up to five areas, each as a rectangle (length × width), a circle (diameter), or a direct area, plus the fill depth, and it returns the volume in cubic feet, cubic yards, and cubic metres together with the tonnage from the material density.
Material presets cover crushed stone and gravel at 105 lb/ft³ (1682 kg/m³), pea gravel at 96 lb/ft³, sand at 100 lb/ft³, crusher run and dense-grade base at 125 lb/ft³, riprap at 165 lb/ft³, and topsoil at 80 lb/ft³, all editable to match your supplier. A compaction allowance (about 10-15% for compacted base courses, 0 for loose decorative fill) and a waste factor scale the order quantity, and the tool converts it into standard 0.5 ft³ bags for small jobs and 10 yd³ truckloads for bulk delivery.
How It Works
- Pick imperial (ft, in, lb/ft³) or metric (m, mm, kg/m³) units, then add one row per area, choosing rectangle (L × W), circle (diameter), or direct area per row.
- Enter the fill depth (in or mm) and pick a material preset — crushed stone, pea gravel, sand, crusher run, riprap, or topsoil — or type your supplier’s loose density.
- The calculator sums the in-place volume V = Σ area × depth (circle area = πd²/4), then applies the compaction and waste allowances: order volume = V × (1 + compaction/100) × (1 + waste/100).
- Mass = order volume × density is reported in US short tons and metric tonnes, alongside ft³, yd³, and m³, a 0.5 ft³ bag count, and the number of 10 yd³ truckloads, both rounded up.
Worked Example
A 10 ft × 10 ft shed pad gets 3 in of crushed stone. The in-place volume is 100 × (3/12) = 25 ft³ = 0.926 yd³. At the 105 lb/ft³ loose density the mass is 25 × 105 = 2625 lb = 1.31 short tons (1.19 tonnes) with no compaction or waste allowance. Ordered in standard 0.5 ft³ bags that is 50 bags, or a fraction of one 10 yd³ truckload. Adding a 10% compaction allowance for a tamped base raises the order to 27.5 ft³ and about 1.44 tons.
Formulas
- In-place volume
V = Σ ( A_i ) × d- Order volume with allowances
V_order = V × (1 + c/100) × (1 + w/100)- Mass and tonnage
M = V_order × ρ ; short tons = M_lb / 2000 ; tonnes = M_kg / 1000- Bags and truckloads
N_bags = ceil( V_order[ft³] / 0.5 ) ; N_trucks = ceil( V_order[yd³] / 10 )
Standards & References
- ASTM C29 bulk density (unit weight) and voids in aggregate
- ASTM D2940 graded aggregate base and subbase materials
- AASHTO M 43 standard sizes of coarse aggregate
Frequently Asked Questions
How much gravel do I need per square foot?
Multiply the area by the depth in feet: each inch of depth needs 1/12 ft³ of gravel per square foot, or about 8.75 lb at the typical 105 lb/ft³ crushed-stone density. A 100 ft² path at 3 in therefore needs 25 ft³ (0.93 yd³), roughly 1.3 tons before any compaction or waste allowance.
How many cubic yards of gravel are in a ton?
At 105 lb/ft³, one cubic yard of crushed stone weighs 27 × 105 = 2835 lb, about 1.42 short tons, so one ton covers roughly 0.7 yd³. Lighter materials go further: a yard of topsoil at 80 lb/ft³ is about 1.08 tons, while dense crusher run at 125 lb/ft³ is nearer 1.69 tons per yard.
What density should I use for crushed stone, sand, or base course?
Loose crushed stone and gravel typically run 100 to 110 lb/ft³ (105 is a good estimating value), pea gravel about 96 lb/ft³, dry sand about 100 lb/ft³, and dense-graded crusher run 120 to 130 lb/ft³ because its fines fill the voids. Riprap is around 165 lb/ft³ and topsoil about 80 lb/ft³. Suppliers usually quote a tons-per-yard figure you can convert and enter directly.
Should I add a compaction factor when ordering gravel?
Yes, when the layer will be compacted. Granular base and crusher run lose roughly 10-15% of loose volume under a plate compactor or roller, so order that much extra to reach the design compacted thickness. Leave the allowance at 0% for loose applications such as decorative gravel, drainage stone, or topsoil spread without compaction.
How deep should a gravel driveway or base layer be?
A gravel driveway is usually built 8 to 12 in thick in total, placed as two or three compacted lifts of 3 to 4 in each, often with larger stone at the bottom and crusher run on top. Walkways and patio bases commonly use 3 to 4 in, and drainage layers 4 to 6 in. Calculate each lift separately if the materials differ.
How many bags of gravel equal a cubic yard?
A cubic yard is 27 ft³, so it equals 54 of the standard 0.5 ft³ bags sold at home centers. Bagged material is convenient below about half a yard, but bulk delivery is far cheaper for bigger jobs; this calculator shows both the bag count and the number of 10 yd³ truckloads so you can compare.