How Much Pea Gravel Do I Need for My Backyard?
Summary: The amount of pea gravel you need depends on the size of the area and the depth of the gravel. Measure the length and width of your project, choose the installation depth, and use the coverage tables below to estimate how many cubic yards to order. For most backyard projects, ordering 5 to 10 percent extra helps prevent shortages.
12mm washed round gravel, often called pea gravel, is a popular choice for backyard paths, landscape beds, patios, and decorative areas. Its smooth, rounded shape gives outdoor spaces a clean finish and allows water to drain through the surface.
Measure the Project Area
Start by measuring the length and width of the area you want to cover.
Use this formula:
Length × Width = Square Feet
| Area Measurements | Total Area |
|---|---|
| 10 ft × 20 ft | 200 sq ft |
| 15 ft × 15 ft | 225 sq ft |
| 20 ft × 20 ft | 400 sq ft |
If your backyard has curves or an uneven shape, divide the area into smaller sections. Measure each section and add the totals together.
Choose the Right Gravel Depth
The installation depth affects how much gravel you need. It also affects how the finished area performs.
| Project Type | Recommended Depth |
|---|---|
| Decorative landscape beds | 2 inches |
| Garden paths and walkways | 2 to 3 inches |
| Patios and seating areas | 3 inches |
| Areas around trees and shrubs | 2 inches |
A deeper gravel layer gives better coverage and helps reduce exposed soil. For paths and seating areas, edging can help keep the round gravel in place.
12mm Washed Round Gravel Coverage
One cubic yard contains 27 cubic feet of material. Use the table below as a quick estimate.
| Gravel Depth | Approximate Coverage per Cubic Yard |
|---|---|
| 1 inch | About 324 sq ft |
| 2 inches | About 162 sq ft |
| 3 inches | About 108 sq ft |
| 4 inches | About 81 sq ft |
Actual coverage can change based on the ground condition, compaction, and how evenly you spread the gravel.
How to Calculate Cubic Yards
You can calculate the amount of gravel you need with this formula:
Length in feet × Width in feet × Depth in feet ÷ 27 = Cubic Yards
Convert the gravel depth from inches to feet before using the formula:
- 1 inch = 0.083 feet
- 2 inches = 0.167 feet
- 3 inches = 0.25 feet
- 4 inches = 0.333 feet
Example Gravel Calculations
| Project | Area | Depth | Estimated Gravel Needed |
|---|---|---|---|
| Garden path | 160 sq ft | 2 inches | About 1 cubic yard |
| Backyard patio | 320 sq ft | 2 inches | About 2 cubic yards |
| Seating area | 216 sq ft | 3 inches | About 2 cubic yards |
| Landscape bed | 80 sq ft | 2 inches | About 0.5 cubic yard |
Round up when your calculation falls between the available bag sizes. This gives you enough material to cover low spots and uneven areas.
Where Can You Use 12mm Washed Round Gravel?
12mm washed round gravel works well for many residential landscape projects, including:
- Garden paths
- Backyard walkways
- Decorative landscape beds
- Patio and seating areas
- Around trees and shrubs
- Drainage areas
- Dog runs
- Areas around stepping stones
The stone is washed to remove most of the fine material. This helps water pass through the gravel and reduces dust.
Is 12mm Washed Round Gravel the Same as Pea Gravel?
12mm washed round gravel is often described as pea gravel because of its small size and rounded shape. Product names and exact stone sizes can vary between suppliers.
When ordering, check the listed size, colour, and stone type. This will help you choose a product that matches the look and use of your project.
Should You Install Landscape Fabric?
Landscape fabric is optional, but it can help keep the gravel separate from the soil below.
| Benefit | How It Helps |
|---|---|
| Separates gravel from soil | Helps prevent the gravel from sinking into soft ground |
| Reduces weed growth | Limits some weeds from growing through the gravel |
| Supports maintenance | Helps keep the gravel layer more even |
Landscape fabric does not stop all weeds. Seeds can still land and grow in dust or organic material that collects on top of the gravel.
Prepare the Area Before Installing Gravel
Good site preparation helps the gravel stay level and reduces future maintenance.
- Mark the project area.
- Remove grass, roots, and loose soil.
- Grade the ground so water moves away from buildings.
- Compact the soil or base material.
- Install landscape fabric if needed.
- Add edging around paths and patios.
- Spread the gravel to the planned depth.
- Rake the surface until it is even.
Order Extra Gravel
Uneven ground, settling, and small changes during installation can increase the amount of gravel you need. Add 5 to 10 percent to your estimate before ordering.
For example, if your project needs 2 cubic yards, consider ordering about 2.1 to 2.2 cubic yards when the supplier offers that option. If the material comes in set bag sizes, round up to the next available size.
12mm Washed Round Gravel Delivery in Calgary
If you are planning a backyard project in Calgary, you can order 12mm Washed Round Gravel for paths, landscape beds, decorative areas, and drainage projects.
Gravel delivery can save time and reduce the need to transport heavy material in a personal vehicle. Before placing your order, confirm the project measurements, gravel depth, bag size, and delivery location.
Final Thoughts
To calculate how much 12mm washed round gravel you need, measure the project area and choose the right depth. One cubic yard covers about 162 square feet at a depth of 2 inches or about 108 square feet at a depth of 3 inches.
Use the coverage tables as a guide and order 5 to 10 percent extra for uneven ground and settling. Calgary homeowners can view our 12mm Washed Round Gravel for backyard and landscape projects.