Free Online Concrete & Gravel Calculator
Calculate Cubic Yards and Bags Needed for Concrete, Gravel, or Mulch
Need to use Concrete & Gravel Calculator right now?
Ordering concrete, gravel, sand, or mulch requires knowing the volume you need, not just the surface area — a patio slab or a gravel driveway has depth as well as length and width, and getting that third dimension into the calculation is where manual math most often goes wrong.
Works for concrete, gravel, sand, or mulch — just enter the area and fill depth. Bag count assumes standard 80lb pre-mix bags yielding about 0.6 cubic feet each.
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Features
- Runs entirely in your browser
- Privacy-first — your data is never uploaded
- Real-time, instant results
- 100% free, no sign-up required
- Works on desktop, tablet, and mobile
- No installation needed
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About Concrete & Gravel Calculator
Ordering concrete, gravel, sand, or mulch requires knowing the volume you need, not just the surface area — a patio slab or a gravel driveway has depth as well as length and width, and getting that third dimension into the calculation is where manual math most often goes wrong.
This calculator multiplies your area's length, width, and depth to get cubic feet, then converts that to cubic yards (the unit most bulk material suppliers quote pricing in) and to the number of standard 80-pound pre-mixed bags you'd need if buying bagged material instead of bulk delivery.
It works identically for concrete, gravel, sand, topsoil, or mulch — just enter the footprint and how deep you want the material, and adjust the bag-yield constant if your specific product's bag size differs from the standard 80-pound assumption.
How it works
- Enter the area dimensions. Input the length and width of the area in feet.
- Enter the fill depth. Input how deep the material layer should be, in inches.
- Read the volume needed. See cubic feet, cubic yards, and estimated bag count instantly.
Examples
10ft x 10ft patio slab, 4 inches deep
Input
Length: 10, Width: 10, Depth: 4 inches
Output
33.3 cubic feet, 1.24 cubic yards, ~56 bags (80lb)