Calculator
MOT Type 1 sub-base calculator
Tonnes of MOT Type 1 = area × compacted depth × about 2.1, plus around 10 percent for compaction and levels; at 100 mm a tonne covers roughly 4.5 m².
Enter your sizes, see the materials and a diagram, then send the list for a delivered price.
Quantities are estimates using standard UK rules of thumb and are shown with their working. We check them against your job before we price anything.
How the calculation works
- Volume = area × compacted depth
- Tonnes = volume × 2.1, + 10%
- Bulk bags ≈ tonnes ÷ 0.85 (bag weights vary)
Worked example
A driveway 5 m × 8 m at 150 mm: 6 m³ × 2.1 = 12.6 tonnes, plus 10% = about 13.9 tonnes, or around 17 bulk bags.
What to order with it
- MOT Type 1 Sub-base: Crushed stone sub-base for drives, patios and slabs.
- Ballast & Gravel: All-in ballast, shingle, pea gravel and decorative stone.
- Building & Sharp Sand: Soft building sand, sharp sand and plastering sand.
Quantities are estimates. Pack sizes, bag weights and coverage vary by manufacturer; we confirm them on your quote.
Questions
How much MOT Type 1 do I need?
Multiply the area by the compacted depth to get cubic metres, then allow about 2.1 to 2.2 tonnes per cubic metre. At 100 mm deep, a tonne covers roughly 4.5 square metres.
How much ballast for a cubic metre of concrete?
Roughly 2 to 2.2 tonnes of all-in ballast with about 15 bags of cement at a 1:5 mix. Our concrete calculator works out your slab or footing.
Send your list, get a delivered price
Tell us what you need and where it is going. We check the quantities and come back with a delivered price before you commit.