Garden & Landscaping calculator
Patio Base Calculator
Estimate patio sub-base aggregate volume and weight from length, width, layer depth, bulk density and an extra allowance.
Estimate patio sub-base aggregate volume and weight from length, width, layer depth, bulk density and an extra allowance. Start with measurements from the actual job and use manufacturer or supplier figures wherever the form asks for coverage, yield, density, spacing or pack size. Watch depth and bulk density in particular. A patio sub-base should be calculated to its compacted finished depth. The loose delivered volume or tonnage can be higher depending on aggregate grading and compaction.
What you need to enter
The Patio Base Calculator uses the following project information to calculate the result.
- Length
- Width
- Depth
- Material density
- Extra allowance (%)
Calculator result
Volume and estimated weight
How the Patio Base Calculator works
The Patio Base Calculator multiplies the paved area by the intended compacted sub-base depth to obtain finished base volume, then applies the selected allowance and optional density conversion. Because delivered aggregate may compact during installation, the finished-depth calculation should be checked against the supplier's loose-to-compacted guidance. The result is therefore a base-course take-off rather than a generic soil or decorative-stone estimate.
Patio Base Calculator worked example
Patio Base Calculator example: A 24 m² patio with a planned compacted sub-base depth of 100 mm needs 2.40 m³ of compacted base material before an allowance for level variation and compaction. Order using the supplier's bulk density or bag coverage. This example shows the arithmetic only; on a live job, review depth and bulk density before turning the result into an order or final size.
Important calculation assumptions
For sub-base aggregate volume beneath a patio, a patio sub-base should be calculated to its compacted finished depth. The loose delivered volume or tonnage can be higher depending on aggregate grading and compaction.
Frequently asked questions
How do I set up accurate inputs for the Patio Base Calculator?
To estimate sub-base aggregate volume beneath a patio, measure length, width and finished layer depth. Use a density that matches the material in the condition it will be supplied or compacted. Use measured or manufacturer-specific values wherever they are available.
Why should I prioritise depth and bulk density over extra decimal precision in the Patio Base Calculator?
A sensible Patio Base Calculator result depends on getting depth and bulk density right. A patio sub-base should be calculated to its compacted finished depth. The loose delivered volume or tonnage can be higher depending on aggregate grading and compaction.
How should I round the Patio Base Calculator result for purchasing?
Once the Patio Base Calculator has produced a result, use the compacted base volume as the design target, then convert to loose delivered aggregate using the supplier's compaction or tonnage guidance.