Landscape Rock Calculator
Enter your dimensions above and hit Calculate to see how much rock you need.
Frequently Asked Questions
The amount of landscape rock depends on three factors: the area to cover (length Γ width), the desired depth, and the rock type. A standard decorative rock bed uses 2-3 inches of depth. For a typical 200 square foot area at 3 inches deep, you would need approximately 0.93 tons of pea gravel or 0.97 tons of river rock. Use our calculator above to get an exact estimate for your specific project dimensions and preferred rock type.
For most decorative landscaping, 2-3 inches of rock depth is ideal. Smaller rocks like pea gravel work well at 2 inches, while larger river rocks (2-3 inch diameter) need 3-4 inches of depth for full ground coverage. For walkways and high-traffic areas, use 3-4 inches over a compacted base. Drainage applications like French drains require 6-12 inches of gravel. If using landscape fabric underneath, you can sometimes get away with slightly less depth as the fabric prevents rocks from sinking into soil.
The weight per cubic yard varies significantly by rock type. Pea gravel weighs approximately 1.30 tons per cubic yard, river rock about 1.35 tons, crushed granite about 1.28 tons, and lava rock only about 0.68 tons per cubic yard due to its porous structure. A standard rule of thumb is that most gravel and crushed stone products weigh between 1.2 and 1.5 tons per cubic yard when measured in their loose, bulk state. Always specify the rock type when ordering to ensure accurate weight estimates.
Buying rock in bulk (by the ton or cubic yard) from a landscape supply yard is almost always cheaper than purchasing bags from a retail store. Bulk rock typically costs $30-80 per ton for common varieties, while bagged rock at home improvement stores can cost the equivalent of $100-200 per ton when you calculate the per-unit price. However, bulk delivery usually requires a minimum order (often 1-3 tons) and delivery fees of $50-150. For very small projects under 50 square feet, bags may be more practical.
Pea gravel consists of small, rounded stones typically 1/8 to 3/8 inch in diameter with smooth edges. River rock is larger, ranging from 1 to 5 inches in diameter, and has been naturally rounded by water erosion. Pea gravel compacts more densely, works well for walkways and fills, and costs less per ton. River rock is better for decorative beds, around plants, and in dry creek beds where visual appeal is primary. River rock allows better water drainage than pea gravel due to larger gaps between stones.
Landscape fabric (weed barrier) is recommended under most decorative rock installations. It prevents weeds from growing up through the rocks and keeps the rocks from sinking into the soil over time. For best results, use commercial-grade woven landscape fabric (not the thin black plastic sheets), overlap seams by 6-12 inches, and secure with landscape staples every 12-18 inches. Note that organic debris will eventually accumulate on top of the fabric and support weed growth, so periodic maintenance is still needed.
For irregular or curved areas, divide the space into approximate rectangles, circles, or triangles and calculate each section separately, then add them together. For a circle, use the formula: area = Ο Γ radiusΒ². For a triangle: area = 0.5 Γ base Γ height. Alternatively, you can take the longest and widest measurements of the irregular area, calculate as if it were a rectangle, and then multiply by 0.8 to account for the irregular shape. Adding 5-10% extra material is wise for complex shapes.
Delivery fees for bulk landscape rock typically range from $50 to $150 depending on the distance from the supplier and the quantity ordered. Many landscape supply yards offer free delivery for orders over 5-10 tons. Standard delivery uses a dump truck that deposits the material in your driveway or as close to the project area as the truck can access. If your site has limited access, you may need a smaller truck or wheelbarrow transfer, which costs extra. Always confirm delivery details and site accessibility before ordering.
For drainage applications, angular crushed rock in the 3/4 to 1-1/2 inch range is ideal because the irregular shapes create consistent void spaces that allow water to flow freely. Crushed granite, limestone, and basalt are popular choices for French drains, dry wells, and foundation drainage. Avoid using round rocks like pea gravel or river rock for structural drainage as they shift and compact, reducing water flow over time. For best results, wrap drainage rock in geotextile fabric to prevent soil infiltration.
What Is a Landscape Rock Calculator?
A landscape rock calculator takes the guesswork out of ordering decorative stone, gravel, or crushed rock for your yard. You enter the length and width of the area you want to cover, set your target rock depth, pick your rock type, and the calculator tells you exactly how many tons, cubic yards, and bags you need β along with an estimated material cost.
It works for garden beds, pathways, dry creek beds, driveways, and any other area where you're laying landscaping rocks. The calculator accounts for the fact that different rocks have different bulk densities β lava rock weighs far less than basalt per cubic foot, which dramatically affects how much you need to order.
Homeowners use it before heading to the landscape supply yard. Contractors use it to write accurate material estimates for clients. If you've ever ordered too little rock and needed a second delivery β or ordered too much and paid for material you didn't use β this tool exists to solve that exact problem.
Want to understand the rock types and what works best for different projects? Check out our pea gravel vs river rock comparison or our rock depth guide for project-specific recommendations. You can also learn more about how we build our calculators.
Using the Calculator β Step by Step
Landscape Rock Guide: Choosing the Right Stone
Not all landscape rock performs the same way. The right choice depends on your project, soil type, climate, and aesthetic goals. Here's what you need to know about the most common options.
Pea Gravel vs River Rock
Pea gravel (1/8β3/8 inch diameter) is the most versatile and affordable option, typically running $40β$75 per ton. Its small, rounded stones compact well, making it ideal for playground surfaces, pet areas, and tight pathways. River rock (1β5 inch diameter) costs more β $60β$120 per ton β but its natural, smooth appearance suits decorative beds, dry creek beds, and around water features. River rock's larger size means better drainage but also more rock shifting underfoot.
For a head-to-head breakdown, read our full pea gravel vs river rock comparison.
Best Rocks for Drainage
If your project involves water management β French drains, dry wells, or areas that flood β angular crushed rock in the 3/4 to 1-1/2 inch range outperforms rounded river rock. Crushed granite, limestone, and basalt all work well because their irregular shapes create consistent void spaces that channel water effectively. Avoid pea gravel in drainage applications; its uniform roundness causes it to shift and compact, reducing water flow over time. See our complete drainage rock guide for details.
How Deep Should You Lay Landscape Rock?
Depth recommendations vary by use case. Decorative garden beds need 2β3 inches to suppress weeds and look full. High-traffic pathways and stepping stone areas need 3β4 inches to stay stable underfoot. Driveways should have 4β6 inches over a compacted gravel base. Drainage applications typically require 6β12 inches depending on depth to the drain. Using too little rock results in soil bleeding through the surface β a common mistake on first-time projects. Our depth guide by project type covers each scenario.
Cost Per Ton by Rock Type (2025 Averages)
Prices vary by region and supplier, but these ranges give you a realistic baseline for planning:
- Pea gravel: $40β$75 per ton
- Crushed granite: $45β$70 per ton
- Crushed limestone: $40β$65 per ton
- River rock (1β3"): $60β$120 per ton
- Basalt/Trap rock: $55β$90 per ton
- Lava rock: $75β$130 per ton
- Marble chips: $100β$175 per ton
- Quartzite: $80β$140 per ton
- Flagstone/Slate: $200β$350 per ton
Bulk delivery from a landscape supply yard is typically 40β60% cheaper per unit than buying bagged rock at a home improvement store. For orders over 5 tons, many suppliers include delivery at no extra charge. Read our 2025 landscape rock cost guide for a full breakdown.
Who Should Use This Calculator?
This tool is built for anyone planning a landscaping project that involves decorative stone, gravel, or crushed rock. Here's who uses it most:
- Homeowners planning garden beds or pathways β you want to know exactly how much to order before you call the supply yard, not after you run short halfway through installation.
- Landscape contractors writing bids β accurate material estimates protect your margin. A 10% error on a 20-ton order at $60/ton is $120 out of pocket.
- DIYers tackling their first rock project β you need to understand the difference between cubic yards and tons, and why rock type changes the math significantly.
- Property managers maintaining commercial grounds β bulk orders for large properties need precise quantity estimates to justify supplier quotes.
- Irrigation and drainage contractors β French drain rock quantities require the same volume/weight math this calculator handles.
Not sure where to start? Try the presets above β βGarden Bed 4Γ8β or βPathway 20Γ3β will give you an instant example of what the calculator produces. Then adjust the numbers to match your actual project.
For hands-on installation advice, check out our step-by-step rock installation guide. If you're weighing rock against organic mulch, our rock vs mulch comparison breaks down the long-term tradeoffs.
ToolSite Team
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