UK MOT Type 1 calculator
MOT Type 1 Calculator UK
MOT Type 1 is a common compactable sub-base material for UK paving projects. Use this calculator page to estimate cubic metres, tonnes, and bulk bags from area and compacted depth.
Quick answer
- 20 m2 at 75 mm depth needs about 1.65 m3 or 3.30 tonnes.
- 20 m2 at 100 mm depth needs about 2.20 m3 or 4.40 tonnes.
- 20 m2 at 150 mm depth needs about 3.30 m3 or 6.60 tonnes.
MOT Type 1 estimates for 20 m2
| Area | Compacted depth | Cubic metres | Tonnes | 850 kg bulk bags |
|---|---|---|---|---|
| 20 m2 | 75 mm | 1.65 m3 | 3.30 t | 4 |
| 20 m2 | 100 mm | 2.20 m3 | 4.40 t | 6 |
| 20 m2 | 150 mm | 3.30 m3 | 6.60 t | 8 |
| 20 m2 | 200 mm | 4.40 m3 | 8.80 t | 11 |
Assumes 10% allowance and 2.0 tonnes per cubic metre. Actual loose material and supplier bag weights vary.
Interactive estimator
Paver Base calculator
Example 10x10 patio: base is about 1.36 cu yd, 2.17 tons, or 74 half-cubic-foot bags.
Enter your own length, width, depth, density, and bag size to create a supplier order.
How much MOT Type 1 do I need?
Calculate compacted volume from area x depth, add an allowance, then convert to tonnes using supplier density. The table uses 2.0 tonnes per cubic metre as a planning density.
For merchant orders, divide tonnes by the bag weight and round up. For loose loads, ask the supplier how they price partial tonnes.
When to use a deeper MOT Type 1 layer
Use a deeper layer for driveways, weak ground, poor drainage, or areas likely to carry heavier loads. Pedestrian patios and paths are usually less demanding than vehicle areas.
If the ground is soft or the project carries vehicles, use these numbers only for early budgeting and confirm the build-up locally.
Helpful next step
Use the subbase calculator for custom areas and depths, or the complete estimator for pavers, sand, edging, and total project cost.