Crushed stone under a patio
Paver Base Calculator for Gravel
A 16 × 12 ft patio with 6 in of compacted base needs 3.56 cu yd in place, about 6.6 tons of crushed stone.
Sources checked
Your estimate
3.56 cu yd
96 cu ft over 192 sq ft at 6 in deep.
- Approximate order weightRounded up to the next 0.1 ton; check your supplier's actual material density.6.6 short tons
- Estimated loose truck volumeConverted from the order weight with WSDOT loose truck density.4.47 cu yd
The footprint matches the finished patio; add any specified base extension beyond its edges to the dimensions above.
How to calculate paver base
- Measure the area to receive the compacted base. Multiply length by width in feet. If your edge detail extends the base beyond the pavers, include that extension in both dimensions.
- Multiply square feet by the compacted depth in inches, then divide by 12 for cubic feet and by 27 for cubic yards.
- For the 16 × 12 ft example: 192 sq ft × 6 in ÷ 12 ÷ 27 gives 3.56 cu yd of compacted base. Multiply by a local compacted tons-per-yard value to order by weight.
Our weight estimate uses WSDOT's crushed surfacing base course, measured compacted on a roadway. It is a reference density, not a product guarantee for your aggregate. The separate WSDOT truck density converts the rounded weight into an approximate loose volume. WSDOT Design Manual, Exhibit 620-1 (Sep 2024)
- Typical patio base, compacted
- 6–8 inUnilock Basic Tech Guide (2024)
- Poorly drained clay, pedestrian surface
- 8–12 inUnilock Advanced Tech Guide (2019)
- Reference compacted base weight
- 1.85 short tons per cu ydWSDOT Design Manual, Exhibit 620-1 (Sep 2024)
- Reference loose truck weight
- 1.48 short tons per cu ydWSDOT Design Manual, Exhibit 620-1 (Sep 2024)
Base amounts at common patio depths
| Compacted depth | Volume | Order weight | Loose truck volume |
|---|---|---|---|
| 6 in | 3.56 cu yd | 6.6 tons | 4.47 cu yd |
| 8 in | 4.74 cu yd | 8.8 tons | 5.97 cu yd |
| 12 in | 7.11 cu yd | 13.2 tons | 8.95 cu yd |
Before ordering base rock
Choose the compacted depth for the soil, drainage and expected load. Unilock gives a deeper range on poorly drained clay; ask your paver supplier which graded aggregate to use and what one loose or compacted cubic yard of that material weighs. Unilock Basic Tech Guide (2024); Unilock Advanced Tech Guide (2019)
This page counts the base only. The paver sand calculator measures the screeded layer above it; the paver patio planner includes pavers, bedding, joints and edging in one shopping list.
Paver base questions
How much paver base do I need?
Multiply length by width for square feet, then by the compacted depth in inches and divide by 324 for cubic yards. Our 16 × 12 ft example at 6 in needs 3.56 cu yd compacted. At the WSDOT reference density, order about 6.6 short tons.
How many tons of paver base for 100 square feet?
At 6 in compacted depth, 100 sq ft is 1.85 cu yd in place. Using the WSDOT reference weight of 1.85 short tons per compacted cubic yard gives about 3.5 tons. Ask your aggregate supplier for its actual weight and gradation.
How deep should a paver patio base be?
Unilock gives 6–8 in of compacted base for a typical patio, and 8–12 in for poorly drained clay in its pedestrian table. Soil, drainage and loads change the design; this calculator lets you enter the specified depth.
Are compacted and loose cubic yards the same?
No. The 3.56 cu yd is the designed volume after compaction. At WSDOT's separate reference weights, the 6.6 ton order occupies about 4.47 cu yd loose on the truck. Actual delivered volume varies by material and moisture.
A planning aid, not an engineering calculation: your local code and building inspector have the final word. Terms