Gravel Calculator

This free gravel calculator computes the volume needed for driveways, walkways, crushed stone pads, road base layers, decorative gravel areas, and parking zones using shape-based volume formulas. Enter your layout’s length, width, and depth, and calculate using the same logic found in our material volume calculator. Results are shown instantly in cubic feet, meters, or yards for planning or delivery.

What Is Construction Gravel?

Gravel is a granular aggregate formed by natural weathering or mechanical crushing of rock, producing fragments between 2 mm and 64 mm in size. Common varieties include pea gravel, crushed limestone, decomposed granite, and recycled concrete aggregate. Owing to its angular interlock and permeability, gravel forms the base layer of driveways, roadbeds, retaining-wall backfill, and drainage trenches. Correct volume estimation guarantees proper thickness, load distribution, and material economy.

Sourcing and Delivery

Bulk gravel arrives in ½-ton bags, 1-m³ mega sacks, or 10-to-20 ton tipper trucks. Suppliers price by ton, so density—ranging from 1.4 t/m³ for pea gravel to 1.8 t/m³ for crushed limestone—affects final cost. Delivery scheduling must account for site access, weather, and spreading equipment. Pre-calculating cubic meters or yards prevents costly second trips or onsite surplus stockpiles.

Layer Thickness and Coverage

Driveways typically require a 100 mm sub-base of ballast followed by 50 mm of decorative gravel. Walkways need only 50 mm total, while French drains demand trench depths of 200 mm or more. A gravel calculator multiplies area by desired layer thickness—converted to meters—to return a precise cubic-volume requirement. Builders often add 5 % contingency for compaction and grading losses.

Compaction and Stabilisation

After placement, gravel is compacted with vibrating plate tampers or rollers to reduce voids and increase bearing capacity. Geotextile membranes beneath the layer prevent soil migration and rutting, while edge restraints maintain width. For high-traffic surfaces, a resin-bound or asphalt top course may be applied. Properly compacted gravel bases extend pavement life and improve drainage performance.

Drainage and Maintenance

Gravel’s high void ratio allows rapid water infiltration, minimising puddling. Over time, fines can clog pores; periodic raking redistributes stones and restores permeability. Replenishment every two to three years offsets losses from migration and dust. Using volume records from the original calculator run simplifies reorder quantities and budgeting for upkeep.

• Measured trench size: 30 × 8 × 0.33 ft
• Used gravel calculator → 79.2 cubic feet
• Confirmed slope-adjusted shapes using volume calculator
• Ordered exact amount, no surplus

This step-by-step saved us time and avoided waste during driveway prep.