MOT Type 1 Calculator
Find how many tonnes and bulk bags of Type 1 you need for a path, patio or drive base.
Measure your project
Your answer
That is 1.60 m³ before packing.
If you buy bulk bags
Under block paving, Interpave gives up to 200 mm of sub-base on soft ground. For a drive or anything that holds weight, check your local building rules or ask a builder or engineer.
What it costs
£75 a bulk bag, with VAT, is the middle of only 3 UK sellers (Oct 2026). Treat it as a rough guide, and ask your supplier.
Quick answers
- A 4 × 3 m base, 100 mm deep
- About 2.50 tonnes. That is 4 bulk bags of 800 kg.
- Weight of 1 m³, as laid
- About 2.08 tonnes, from what Wickes says its bag covers.
- How deep for a drive?
- 150 mm, packed. Under block paving, Interpave gives up to 200 mm of sub-base, by how firm the ground is.
- Price
- About £75 a bulk bag, with VAT. It is the middle of only 3 sellers, so treat it as a rough guide.
How to work it out
- Measure the base in metres. Length × width gives its area in m².
- Choose the depth it will have once packed. Turn mm into metres by dividing by 1,000.
- Area × depth gives the packed volume in m³.
- Type 1 weighs about 2.08 tonnes per m³ as laid. Volume × 2.08 gives tonnes.
- Tonnes ÷ 0.8 gives 800 kg bulk bags. Round up to a whole bag.
4 × 3 × 0.1 = 1.2 m³ (packed)
1.2 × 2.08 = 2.50 tonnes
2.50 ÷ 0.8 = 3.1 → 4 bags
Loose: 1.2 × 1.33 = 1.6 m³
Type 1 for common sizes
Pick the row closest to your base. Both depths are after packing.
| Size | Tonnes, 100 mm | Bags | Tonnes, 150 mm | Bags |
|---|---|---|---|---|
| 3 × 2 m | 1.25 | 2 | 1.87 | 3 |
| 4 × 3 m | 2.50 | 4 | 3.74 | 5 |
| 5 × 4 m | 4.16 | 6 | 6.24 | 8 |
| 10 × 3 m | 6.24 | 8 | 9.36 | 12 |
| 10 × 5 m | 10.40 | 13 | 15.60 | 20 |
Packed depths, no extra. Part bags count as a whole bag.
What one bulk bag covers
Wickes says its 800 kg bag covers about 7.7 m² at 50 mm. That is where our weight of 2.08 tonnes per m³ comes from.
| Depth | 800 kg bag | 850 kg bag |
|---|---|---|
| 50 mm | 7.7 m² | 8.2 m² |
| 100 mm | 3.8 m² | 4.1 m² |
| 150 mm | 2.6 m² | 2.7 m² |
| 200 mm | 1.9 m² | 2 m² |
Bags and prices
Bag sizes vary: 800 kg at Wickes, at least 850 kg at Tippers.
We looked up Type 1 at Wickes, Tippers and Lawsons. The cheapest bag was £52.20 and the dearest £79.92, with VAT. The middle price, £75, is what the calculator uses.
That is only 3 sellers, so treat it as a rough guide.
Packing down: what to type
Type 1 is spread loose, then packed down hard. Loose, it takes about 1.33 times the room, says a Penn State road guide.
- Type the depth you want after packing.
- Your tonnes stay the same. Packing squeezes the stone into less room, but it weighs the same.
- Our 2.08 tonnes per m³ is for stone as laid. So we use the 1.33 only for the loose size, never for the weight.
So spread it thicker first, like this.
| Depth after packing | Spread it about |
|---|---|
| 80 mm | 106 mm |
| 100 mm | 133 mm |
| 150 mm | 200 mm |
| 200 mm | 266 mm |
Type 1 depth for patios, drives and paving
- Patio of slabs: Cemex gives 50–80 mm of hardcore. A concrete bed of 50–80 mm goes on top, then the slabs.
- Drive: about 150 mm of sub-base, says a UK government guide to front gardens. Its drives are 200–250 mm deep in all. That guide is for drives that let rain soak through (permeable).
- Block paving: up to 200 mm of sub-base, says Interpave. Softer ground needs more, and very firm ground may need none.
| How firm the ground is | Sub-base |
|---|---|
| Weakest (CBR under 2%) | 200 mm |
| CBR 3% | 150 mm |
| CBR 4% | 125 mm |
| Firm (CBR 5%) | 100 mm |
| Firmest (CBR over 6%) | None |
CBR is a test of how firm the ground is. A higher number means firmer ground.
Interpave's quick check: drive a 50 mm peg into the ground. If it is hard to get 150 mm in, the ground is firm sand or gravel.
For a drive, or anything that holds weight, check your local building rules or ask a builder or engineer.
Why Type 1 calculators disagree
We looked at 3 other UK Type 1 calculators. 2 of the 3 state a weight: 1.6 or 2.4 tonnes per m³. We use 2.08.
Here is the same 4 × 3 m base, 100 mm deep, with each weight.
| Weight per m³ | Tonnes | 800 kg bags |
|---|---|---|
| 1.6 t | 1.92 | 3 |
| 2.08 t (ours) | 2.50 | 4 |
| 2.4 t | 2.88 | 4 |
A higher weight per m³ gives more tonnes for the same base.
Before you compare answers, check which weight each calculator or supplier uses.
Type 1 or crusher run?
Type 1 is made to a road standard, Clause 803 of the Specification for Highway Works. It is graded from 40 mm stones down to dust.
Crusher run has no standard, says Lightwater Quarries. It is often 40 or 75 mm down to dust, with more fine dust.
Crusher run is lighter, too. Greenvale says a tonne covers about 11 m² at 50 mm. That works out at 1.82 tonnes per m³.
Questions people ask
How much MOT Type 1 do I need?
Take the area in m², times the packed depth in metres, times 2.08. That gives tonnes. A 4 × 3 m base at 100 mm takes about 2.5 tonnes.
How much Type 1 per square metre?
About 208 kg per m² at 100 mm deep, after packing. At 150 mm, it is about 312 kg.
How many tonnes of Type 1 are in 1 m³?
About 2.08 tonnes as laid, from Wickes's cover figure. Before packing, those tonnes fill about 1.33 m³.
How much does a bulk bag of Type 1 cover?
An 800 kg bag covers about 7.7 m² at 50 mm, after packing. At 100 mm, it covers about 3.8 m².
How much Type 1 for a patio?
Cemex gives 50–80 mm of hardcore under a slab patio. A 4 × 3 m patio at 80 mm needs about 2.00 tonnes. That is 3 bulk bags.
How deep should Type 1 be for a drive?
150 mm, packed, say a UK government (DCLG) guide and the Mineral Products Association. Under block paving, Interpave gives up to 200 mm of sub-base.
How much Type 1 for 16 m² at 200 mm deep?
About 6.66 tonnes, after packing. That is 9 bags of 800 kg, or 8 bags of 850 kg.
Is crusher run the same as Type 1?
No. Type 1 is made to a road standard, and graded from 40 mm down to dust. Crusher run has no standard and often has more fine dust.
Where our numbers come from
- Type 1 weight and price: Wickes 800 kg bag (checked Oct 2026)
- 850 kg bulk bags: Tippers aggregates list
- Bulk bag prices: the middle price from 3 UK sellers each (Wickes, Tippers, Lawsons; Oct 2026)
- Packing down: Penn State road-stone guide (8 in loose packs to 6 in)
- Drive depth: UK government front-garden paving guide
- Tarmac drive layers: Mineral Products Association, Asphalt Applications 1
- Sub-base by ground: Interpave, Concrete Block Paving
- Patio build-up: Cemex guide to garden walls and paving
- Type 1 vs crusher run: Lightwater Quarries
- Crusher run weight: Greenvale Products (1 tonne covers about 11 m² at 50 mm)
- Other UK Type 1 calculators: our look at 3 tools (2 state 1.6 or 2.4 t per m³)
Made by BuildersCount. Last checked 3 Oct 2026.
How we work out our numbers About us Found a mistake? Tell us