Calculate how much MOT Type 1 sub-base aggregate you need in tonnes and cubic metres.
Compacted MOT Type 1 weighs around 2.1 tonnes per cubic metre. One bulk bag holds roughly 850 kg.
For a domestic driveway, lay 150–200 mm (6–8 in) of compacted MOT Type 1. Paths and patios usually need 100 mm (4 in).
Loose MOT Type 1 reduces in volume when compacted, so adding 10–20% ensures you order enough to reach your finished depth.
MOT Type 1 is a graded crushed stone sub-base that compacts to a firm, well-draining layer, widely used under driveways, patios and paths.
One bulk bag holds roughly 850 kg, covering about 5 m² at 100 mm or 3.5 m² at 150 mm once compacted. Divide your total tonnage by 0.85 to get the number of bulk bags.
