Gravel Calculator
By Emiliano · Last updated 2026-09-27
Calculate how much gravel you need for driveways, walkways, and landscaping. Enter area and depth for instant tons and cubic yards.
Estimated Material Required
How this calculator works
This calculator determines the required aggregate volume by multiplying the length, width, and depth of your project area. It then applies standard material density factors to convert the volume into estimated weight in tons or metric tonnes. Formula source: AASHTO M147 and state DOT aggregate specifications.
How to Calculate Gravel
Calculating the exact amount of gravel required for a construction or landscaping project prevents costly over-ordering and ensures structural integrity. To calculate gravel manually, you must determine the volume of the space. For imperial measurements, multiply the length in feet by the width in feet to find the square footage. Next, convert your desired depth from inches to feet by dividing by 12. Multiply the square footage by the depth in feet to get the total cubic feet, and then divide by 27 to convert to cubic yards. For example, a standard driveway measuring 30 feet long by 10 feet wide with a depth of 3 inches (7.6 cm) requires 2.78 cubic yards of material.
For metric calculations, the process is simplified. Multiply the length in meters by the width in meters to find the square meters, then multiply by the depth in meters (centimeters divided by 100) to obtain cubic meters. For instance, a walkway measuring 10 meters long by 1.2 meters wide with a depth of 8 centimeters (3.1 inches) requires 0.96 cubic meters of aggregate. To convert volume to weight, multiply the cubic yards by 1.4 (or cubic meters by 1.66) to estimate the tonnage required for standard crushed stone.
What Affects Gravel Coverage
Several variables influence the actual volume and weight of gravel required for a project. The primary factor is compaction. When gravel is spread and compacted using a plate compactor or roller, its volume decreases by approximately 10% to 15%. For heavy-duty bases, such as a 6-inch (15 cm) sub-base for a driveway, you must account for this compaction by ordering extra material. Additionally, the gradation and type of aggregate play a major role; well-graded gravels containing fine particles (like crusher run) pack much tighter than clean, uniform stones like pea gravel, which typically measures 3/8 inch (10 mm) and retains more void space.
Subgrade conditions also impact coverage. If the underlying soil is soft clay or uneven, gravel will sink into the subgrade under load. Installing a geotextile fabric barrier before spreading aggregate prevents soil mixing and preserves the design depth. Moisture content is another variable; wet gravel is heavier and packs differently than dry aggregate, which can slightly alter the weight-to-volume ratio during delivery.
Frequently Asked Questions
How deep should gravel be for a residential driveway?
For standard residential driveways, a minimum total depth of 4 to 6 inches (10 to 15 cm) of compacted gravel is recommended. This is typically laid in multiple layers: a coarse 2 to 3-inch (5 to 8 cm) base layer for drainage and stability, followed by a finer top dressing layer.
What is the difference between a ton and a cubic yard of gravel?
A cubic yard measures volume (3 feet by 3 feet by 3 feet), whereas a ton measures weight (2,000 lbs or 907 kg). Because gravel is highly dense, one cubic yard typically weighs between 1.3 to 1.6 tons (1.18 to 1.45 metric tonnes), depending on the specific rock type and moisture levels.
How do I calculate gravel for a circular or irregular area?
For circular areas, calculate the area using the formula πr² (3.1416 x radius x radius). For irregular shapes, divide the layout into smaller, manageable geometric sections (rectangles and triangles), calculate the volume of each section individually, and sum them up before applying your depth and density factors.