About this calculator

How-to: enter finished area and pick the use category. We apply UK/EU sub-base depths: pedestrian patio 100 mm MOT + 30 mm sand, driveway 150 mm MOT + 40 mm sand, heavy driveway 200 mm MOT + 40 mm sand, shed base 100 mm MOT. Compaction factor ×1.25 (MOT compresses ~20% under a wacker plate). Bulk density: MOT Type 1 ≈ 2.1 t/m³, sharp sand ≈ 1.6 t/m³.

Frequently asked questions

Do I really need geotextile?

Yes for clay or wet ground — it stops sub-base stone punching down into soft ground and prevents weeds. Skip only on very free-draining sandy sub-soil.

MOT Type 1 vs Type 3?

Type 1 (0–63 mm limestone/granite) is the default under paving, drives and buildings. Type 3 (0–40 mm) is open-graded / permeable for SuDS-compliant driveways under new UK/EU planning rules.

Can I use scalpings instead?

Scalpings (Type 1x / recycled crushed concrete) are cheaper and fine under patios and paths. Not accepted under commercial pavements or where a Highways Type 1 certificate is required.

What does the Deck & Paving Sub-base Material Volume Calculator do?

MOT Type 1 / crushed stone, sharp sand and geotextile quantities for a patio, driveway, path or shed base — plus compacted vs loose volume conversion. How-to: enter finished area and pick the use category. We apply UK/EU sub-base depths: pedestrian patio 100 mm MOT + 30 mm sand, driveway 150 mm MOT + 40 mm sand, heavy driveway 200 mm MOT + 40 mm sand, shed base 100 mm MOT. Compaction factor ×1.25 (MOT compresses ~20% under a wacker plate). Bulk density: MOT Type 1 ≈ 2.1 t/m³, sharp sand ≈ 1.6 t/m³.

Is the Deck & Paving Sub-base Material Volume Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Deck & Paving Sub-base Material Volume Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified construction & building professional before committing to a purchase or a job.

What inputs does the Deck & Paving Sub-base Material Volume Calculator need?

Enter values for: Area to lay (m²), Use, Geotextile membrane?, MOT Type 1 (per tonne), Sharp sand (per tonne), Currency. Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Deck & Paving Sub-base Material Volume Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.