Soils & aggregates
MOT Type 1 Calculator
Work out how much MOT Type 1 sub-base you need — in cubic metres, tonnes and bulk bags — then get it delivered to your site.
Volume—cubic metres
You need about—tonnes (incl. compaction)
Or roughly—bulk bags (~0.8 t each)
Based on a compacted density of ~2.1 tonnes per cubic metre. Figures are a guide — confirm exact quantities with your supplier before ordering.
How to use it
Enter the area you are covering and the depth of sub-base, and the calculator returns the volume, the tonnes of MOT Type 1 to order (with a compaction allowance), and how many bulk bags that is.
Typical depths
- Paths & patios — 50–75mm compacted
- Driveways (cars) — 100mm
- Heavy use / soft ground — 150mm
Quick coverage guide
1 tonne of MOT Type 1 covers roughly 10m² at 50mm or 5m² at 100mm once compacted.
Removing spoil to make room for your sub-base? We can take it away by grab lorry and deliver the Type 1 on the same trip — see soils & aggregates.
MOT Type 1 questions
How much does 1 tonne of MOT Type 1 cover?
About 5 square metres at a compacted depth of 100mm, or roughly 10 square metres at 50mm. As a rule of thumb, 1 tonne of MOT Type 1 is close to half a cubic metre once compacted.
How many tonnes of Type 1 are in a cubic metre?
Around 2.1 tonnes per cubic metre once compacted, though this varies a little by source. Loose, as-delivered material is a few percent lighter.
What depth of MOT Type 1 do I need?
Typically 50 to 75mm compacted for paths and patios, and 100 to 150mm for a driveway. Always lay and compact in layers no thicker than about 100mm.
How many bulk bags of Type 1 will I need?
A standard builders bulk bag holds roughly 0.8 tonnes, so divide your total tonnes by 0.8. The calculator above does this for you and rounds up.
Why does the calculator add a compaction allowance?
Type 1 squashes down to about 80 to 85% of its loose volume when compacted, so you need to order more than the finished volume suggests. We add 15% by default - increase it for deep or heavily compacted layers.