What is a Gravel Calculator?
A gravel calculator helps you determine exactly how much aggregate material you need for your construction or landscaping project. Whether you're building a driveway, creating a garden path, filling a drainage trench, or installing a patio base, knowing the precise amount of material saves money and prevents multiple trips to the supplier.
This calculator computes volume in cubic feet and cubic yards, converts to weight in tons based on material density, and provides cost estimates. Understanding these measurements is essential because suppliers sell bulk materials by volume (cubic yards) or weight (tons), and prices vary significantly between ordering too much or making multiple deliveries.
Understanding Volume Calculations
Basic Volume Formulas
Rectangle: V = Length × Width × Depth
Circle: V = π × r² × Depth
Triangle: V = 0.5 × Base × Height × Depth
All measurements should be in the same unit before calculating
Converting to Cubic Yards
One cubic yard equals 27 cubic feet. Most material suppliers quote prices per cubic yard for bulk delivery. To convert: divide total cubic feet by 27 to get cubic yards. When ordering, round up to the nearest half or full yard since suppliers typically don't deliver fractional amounts.
Material Types and Properties
| Material | Density (lbs/cu ft) | Typical Uses |
|---|---|---|
| Gravel | 100 | Driveways, drainage, base material |
| Pea Gravel | 96 | Walkways, patios, playgrounds |
| Crushed Stone | 100 | Driveways, compacted base |
| Sand | 100 | Paver base, concrete mixing |
| Topsoil | 75 | Gardens, lawns, landscaping |
| Mulch | 25 | Garden beds, tree rings |
| Decomposed Granite | 95 | Paths, patios, xeriscaping |
| River Rock | 90 | Decorative, dry creek beds |
Recommended Depths by Application
The depth of material needed depends on its intended use. Deeper layers provide better stability and durability but require more material. Here are standard depth recommendations:
Driveway Applications
- Base layer (crushed stone): 4-6 inches
- Surface layer (gravel): 2-3 inches
- Total depth: 6-9 inches minimum
- Heavy vehicle traffic may require 12+ inches total
Walkways and Patios
- Pea gravel path: 2-4 inches
- Paver base (sand): 1 inch
- Paver base (gravel): 4-6 inches
- Decorative stone: 2-3 inches
Landscaping and Gardens
- Mulch around plants: 2-4 inches
- Topsoil for new beds: 6-8 inches
- Drainage gravel: 4-6 inches
- French drain fill: 6-12 inches
Gravel Size Guide
Gravel and stone come in various sizes, each suited for different applications. Size is typically measured by screen size or diameter:
| Name | Size | Best For |
|---|---|---|
| Pea Gravel | 1/4" - 3/8" | Walkways, drainage, aesthetics |
| #57 Stone | 1/2" - 1" | Driveways, drainage |
| #67 Stone | 3/4" | Drainage, concrete aggregate |
| #411 Gravel | Mixed w/ fines | Compactable base, driveways |
| Crusher Run | Mixed 0-2" | Base material, compacts well |
| River Rock | 1" - 3" | Decorative, drainage |
Coverage Calculations
One Cubic Yard Covers:
- 324 square feet at 1 inch deep
- 162 square feet at 2 inches deep
- 108 square feet at 3 inches deep
- 81 square feet at 4 inches deep
- 54 square feet at 6 inches deep
Compaction and Settling
Fresh gravel and aggregate materials settle and compact over time. When calculating material needs, add 10-15% extra to account for this settling. Compaction rates vary by material:
- Crushed stone with fines: Compacts 10-15%
- Clean gravel: Compacts 5-10%
- Sand: Compacts 15-20%
- Topsoil: Settles 10-15%
- Mulch: Settles 20-30%
Delivery Considerations
Minimum Orders
Most suppliers have minimum delivery amounts, typically 1-2 cubic yards. Smaller quantities may be available for pickup. Delivery fees often include the first load, with additional charges per mile beyond a certain radius.
Access Requirements
- Dump truck clearance: 12-14 feet height minimum
- Road width: At least 10 feet for delivery vehicles
- Ground stability: Trucks can weigh 20+ tons loaded
- Dumping area: Plan where material will be deposited
Cost Factors
Price Ranges by Material
Prices vary significantly by region, availability, and supplier. Typical ranges per cubic yard:
- Crusher run/base gravel: $25-35
- Pea gravel: $40-55
- Crushed stone (#57, #67): $35-45
- Sand: $25-40
- Topsoil: $20-35
- Mulch: $30-45
- Decomposed granite: $45-60
- River rock: $50-75
Delivery Costs
Typical delivery fees range from $50-150 depending on distance and quantity. Some suppliers offer free delivery above certain order amounts. Compare total cost including delivery when shopping multiple suppliers.
Installation Tips
Site Preparation
- Remove vegetation and organic matter
- Grade the area for proper drainage (1-2% slope)
- Install landscape fabric for weed prevention
- Create borders or edging to contain material
- Compact subgrade before adding gravel
Spreading Material
- Work in layers for thick applications
- Rake evenly across the area
- Compact each layer before adding the next
- Maintain consistent depth throughout
Frequently Asked Questions
How do I convert cubic yards to tons?
Multiply cubic yards by the material density factor. For gravel: cubic yards × 1.4 = tons (approximate). For topsoil: cubic yards × 1.1 = tons. For mulch: cubic yards × 0.4 = tons. Each material has different density.
Should I order by weight or volume?
Both methods work. Volume (cubic yards) is easier to calculate from your project dimensions. Weight (tons) is more accurate since it doesn't vary with moisture content. Most residential deliveries are priced by volume.
How much extra should I order?
Add 10-15% to your calculated amount for settling, compaction, and coverage of uneven areas. It's better to have slightly too much than to make another delivery order. Excess material can be stored for maintenance.
Can I pick up gravel myself?
Yes, most suppliers allow pickup. Know your vehicle's payload capacity. A standard pickup truck can safely carry about 1/2 to 1 cubic yard depending on the material weight. Overloading is dangerous and illegal.
How long does gravel last?
Properly installed gravel can last 10-20 years or more. Maintenance includes occasional raking to level, adding material to thin spots, and managing weeds. Crusher run and compacted stone last longer than loose decorative gravel.