Calculator Inputs
Example Data Table
These sample scenarios show typical garden path estimates.
| Scenario | Area (sq ft) | Depth (in) | Allowance (%) | Volume (cu yd) | Weight (tons) |
|---|---|---|---|---|---|
| Small walkway | 60 | 2 | 10 | 0.41 | 0.55 |
| Medium path | 150 | 2.5 | 12 | 1.28 | 1.73 |
| Patio base | 240 | 3 | 15 | 2.56 | 3.46 |
Formula Used
- Rectangle: Area = Length × Width
- Circle: Area = π × Radius²
- Triangle: Area = (Base × Height) ÷ 2
- Custom: Area = user input
- Depth (ft): Depth_ft = Depth_in ÷ 12
- Base volume (cu ft): V = Area × Depth_ft
- Adjusted volume: V_adj = V × (1 + (Compaction% + Waste%)/100)
- Cubic yards: V_cuyd = V_adj ÷ 27
- Tons: Tons = V_cuyd × Density
- Pounds: Lb = Tons × 2000
- Bag count: Bags = ceil(Lb ÷ BagWeightLb)
- Bulk cost: Cost_bulk = Tons × PricePerTon
- Bag cost: Cost_bags = Bags × BagPrice
How to Use This Calculator
- Choose the area shape that matches your project.
- Enter the dimensions or your known square footage.
- Set the depth based on your design and traffic.
- Add compaction and waste allowances for real-world loss.
- Enter your supplier density and pricing for bulk estimates.
- Optionally enter bag size and bag price for comparisons.
- Press calculate to see volume, weight, and costs.
- Download CSV or PDF to share with vendors or clients.
Decomposed Granite Coverage Planning Guide
1) Why coverage calculations matter
Decomposed granite is sold by volume or weight, but installed performance depends on depth and compaction. A small error across a long path can mean a short delivery, extra freight charges, and uneven finishes. This calculator converts your dimensions into cubic feet, cubic yards, tons, and bag counts so purchasing decisions stay consistent.
2) Typical garden depths and use cases
For light foot traffic, many installations target 1.5–2 inches after compaction. Busy walkways and pet areas often use 2–2.5 inches. For base layers beneath pavers or flagstone, 3 inches or more may be required. Entering depth in inches lets you match these common specifications without unit confusion.
3) Compaction allowance in real projects
Loose granite settles when wetted and rolled. A practical compaction allowance is 5–10%, depending on moisture and equipment. If you place 2 inches loose and compact to 1.75 inches, that is about a 14% change, but well-graded material often compacts less. Use a conservative percentage if access is difficult.
4) Waste and spillage planning
Waste accounts for edging buildup, wheelbarrow loss, raking, and small grade corrections. Many crews plan 5–15% waste, with higher values for tight curves, irregular beds, or small deliveries. Combining waste with compaction provides a single allowance that protects your order quantity from field variability.
5) Density and supplier variation
Suppliers may quote density as tons per cubic yard. Common ranges for decomposed granite are roughly 1.2–1.5 tons per cubic yard, but moisture and fines can shift this. If your supplier lists pounds per cubic foot, divide by 2000 and multiply by 27 to convert to tons per cubic yard.
6) Bulk delivery versus bags
Bulk is usually the economical choice once you exceed a few hundred square feet. Bags are useful for small repairs, gated access, or staggered work. The calculator estimates pounds and then rounds bag count up using your bag weight (often 20, 40, or 50 pounds), helping you avoid underbuying.
7) Reading the outputs confidently
Adjusted volume in cubic yards is a common ordering unit, while tons support weight-based quotes. If the tool shows 1.28 cubic yards and 1.73 tons, you can compare a “per yard” price with a “per ton” price without recalculating. Use the cost comparison to choose the best purchasing method.
8) Field checks before ordering
Confirm your measured area, especially with curved paths. Verify whether depth is finished depth or loose depth, and decide on a realistic allowance. If you are building over soft soil, consider a geotextile layer and edging to reduce migration. Ordering slightly extra is cheaper than a second delivery.
FAQs
1) What depth is best for a garden path?
Most footpaths perform well at 1.5–2.5 inches compacted. Use deeper sections for heavy traffic, slopes, or areas that frequently wash. Match depth to edging height and maintenance expectations.
2) How do I estimate compaction?
A 5–10% allowance covers typical settling after watering and rolling. If you only hand tamp, use a higher allowance. Track one small test section to refine the percentage for future orders.
3) What density should I enter?
If you do not have a supplier spec, start around 1.35 tons per cubic yard as a middle value. Moist material can weigh more, while drier or coarser blends may weigh less.
4) Should I buy bulk or bags?
Bulk usually wins for larger areas due to lower unit cost. Bags are convenient for small projects, tight access, or phased work. Compare the bulk cost and bag cost totals shown in the results.
5) Why does the tool add waste?
Waste accounts for spillage, edging buildup, and minor grade corrections. Curves and irregular borders increase loss. Adding waste helps prevent running short, which can cause color mismatch if you buy later.
6) Can I use this for a base layer under pavers?
Yes. Choose the correct area and set depth to your planned base thickness, often 3 inches or more. Confirm your design requirements and local soil conditions before finalizing the depth.
7) How accurate are the results?
Accuracy depends on measurements, depth definition, and density. The calculator provides a strong planning estimate. For final ordering, verify supplier density, delivery minimums, and whether pricing is by ton or yard.