Last updated: March 2026
What Is the Gravel Calculator?
The Gravel Calculator helps you determine exactly how much gravel, crushed stone, or other landscaping material you need for any project. Whether you are building a driveway, laying a garden path, or filling a drainage area, this tool calculates the volume in cubic yards, weight in tons, estimated cost, and even how many dump truck loads to expect. No more guessing at the landscape supply yard.
It supports nine common material types, each with accurate density values so your weight estimates are reliable. You can add up to eight separate areas with different shapes and depths, making it easy to plan complex projects with multiple zones in a single calculation.
How to Calculate Gravel Needed
Step 1: Measure your area. For rectangular areas, multiply length times width to get square footage. A 12-foot by 30-foot driveway is 360 square feet. For circular areas like fire pit surrounds, measure the diameter and the calculator handles the math. Triangular areas just need the base and height.
Step 2: Determine depth. Depth depends on your application. Decorative beds typically need 2 inches. Walkways and paths work well at 3 to 4 inches. Driveways require 4 to 6 inches total for durability. Our driveway quick mode automatically splits this into a 4-inch base layer and 2-inch top layer, which is the industry-recommended approach.
Step 3: Choose your material. Different materials have different densities. One cubic yard of pea gravel weighs about 1.35 tons, while decomposed granite weighs 1.50 tons per cubic yard. Selecting the right material gives you an accurate weight estimate, which is what suppliers use for pricing.
Step 4: Review results. The calculator shows volume (cubic yards and cubic feet), weight (tons and pounds), an estimated cost range based on typical market prices, and the number of dump truck loads needed. Use the depth comparison table to see how changing depth affects material needed and cost.
Frequently Asked Questions
How much gravel do I need for a driveway?
A typical single-car driveway of 10 by 20 feet at the recommended 6-inch total depth (4-inch base layer plus 2-inch top layer) requires about 3.7 cubic yards or roughly 5 tons of gravel. A double-wide 20 by 20 foot driveway doubles that to about 7.4 cubic yards or 10 tons. Use our driveway quick mode for an instant calculation with your exact dimensions.
What is the difference between tons and cubic yards?
Cubic yards measure volume (how much space the material fills), while tons measure weight. The conversion depends on the material density. One cubic yard of pea gravel weighs about 1.35 tons, while one cubic yard of decomposed granite weighs about 1.50 tons. Suppliers typically sell gravel by the ton, so knowing both measurements helps you order accurately and compare prices.
How deep should gravel be?
Depth depends on the application. Decorative landscaping beds need 2 to 3 inches. Walkways and garden paths need 3 to 4 inches. Driveways need 4 to 6 inches total, ideally with a 4-inch compacted base of angular crushed stone and a 2-inch top layer of finer gravel. Drainage projects may need 6 to 12 inches depending on water volume.
How many tons fit in a dump truck?
A standard single-axle dump truck carries about 10 tons (roughly 7 to 8 cubic yards of gravel). A tandem-axle dump truck holds 15 to 18 tons. A tri-axle can carry up to 25 tons. Most residential deliveries use single or tandem-axle trucks. Always confirm weight limits with your delivery company, as local road and bridge restrictions may apply.
Should I order extra gravel?
Yes, always order 5 to 10 percent more than your calculated amount. Uneven ground, compaction during spreading, material that gets pushed outside the work area, and natural settling all consume extra material. Running short mid-project often means paying a second delivery fee, which costs far more than the extra gravel would have.