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Tarmac Calculators

Professional estimation tools for paving and surfacing projects. Accurately calculate tarmac quantities, estimate driveway installation and repair costs, and determine sub-base material requirements for your project.

Driveways & Roads UK Metrics Supported Tonnage Estimates

Available Tarmac Tools

5 Calculators Available

Precision Paving Estimates

Paving materials are expensive, and ordering the incorrect amount can lead to costly delays or wasted material. Our calculators help contractors and homeowners estimate properly.

  • 1Cost Planning: Get realistic brackets for new driveways and resurfacing based on industry norms.
  • 2Material Ordering: Calculate required tonnage of wearing course, base course, and granular sub-base.
  • 3Repair Assessments: Understand the financial difference between patching, overlaying, and full-depth reconstruction.

Paving Tips & Best Practices

Check the Sub-Base

A driveway is only as strong as its foundation. Never skimp on the MOT Type 1 sub-base depth and compaction; it prevents rutting.

Account for Wastage

When ordering tarmac or sub-base tonnage, always factor in 5% to 10% extra for wastage, compaction variations, and edge spillage.

Drainage is Critical

Ensure your design incorporates proper falls (slopes) or linear drainage to prevent standing water, which degrades paving rapidly.

Tarmac & Paving FAQs

What is the difference between tarmac and asphalt?+

While frequently used interchangeably, true tarmac (tarmacadam) relies on a tar-based binder, whereas asphalt uses bitumen—a petroleum by-product. Modern paving almost universally uses asphalt (bitumen macadam or SMA) due to superior durability and environmental safety, even though contractors still colloquially refer to it as 'tarmacking'.

How do I calculate how much tarmac I need?+

To calculate tarmac tonnage, you multiply the surface area (length × width) by the desired compacted depth to find the volume, then multiply by the material's density (typically 2.3 to 2.4 tonnes per cubic meter). Always add a 5% to 10% wastage factor to account for site irregularities.

How thick should a tarmac driveway be?+

A standard domestic driveway typically features a 50mm base course (binder course) topped with a 25mm to 30mm surface course (wearing course), bringing the total tarmac thickness to roughly 75mm to 80mm. This sits upon a compacted MOT Type 1 sub-base, usually 150mm thick.

Is it cheaper to repair or replace a tarmac driveway?+

Patching small potholes or cracks is significantly cheaper than replacing. If the structural integrity of the base is sound, an 'overlay' or 'resurfacing' (adding a new surface layer) offers a middle-ground cost. Full replacement is the most expensive but is necessary if the sub-base is failing or the surface is extensively crazed.

What is MOT Type 1 and why do I need it?+

MOT Type 1 is a granular aggregate sub-base material (often crushed stone or concrete) that compacts to create a highly stable, load-bearing layer. A strong sub-base is essential under tarmac to prevent the surface from sinking, rutting, or cracking under vehicle weight.