Driveway Gravel & Rock Coverage Calculator

75-100mm of surface gravel over a compacted sub-base is the widely recommended depth range for a driveway, with 75mm as the commonly cited minimum needed to resist wheel-rutting under vehicle traffic. A shallower 50mm depth is fine for paths, borders or decorative mulch, but is explicitly not recommended for a driveway that vehicles will drive and park on.

Yes - a compacted MOT Type 1 sub-base (typically 100-150mm, up to 200mm on poor ground) is widely recommended under a gravel driveway. It distributes vehicle weight across the full area and prevents the gravel sinking, rutting or disappearing into soft ground over time, which is the most common cause of gravel driveway failures according to UK aggregate supplier guidance.

They're different decorative aggregate materials with different bulk densities and appearances: pea shingle/gravel is rounded and typically around 1.4-1.6 t/m³, golden gravel/chippings is angular and typically around 1.6-1.8 t/m³ (denser, so you need slightly more tonnage for the same depth and area), and slate chippings is flatter and typically around 1.3-1.5 t/m³. Choose based on the look you want and check your specific supplier's exact density, since it varies by quarry.

A standard bulk ("jumbo" or "builder's") bag of gravel or aggregate holds around 0.85 tonnes - this calculator's figure - though some suppliers quote a slightly different weight (commonly 800kg-1000kg), so check the exact figure with whoever you're buying from, since it directly affects how many bags you need to order.

It depends on your chosen depth and gravel density, not a single fixed figure - as a rough guide, standard 20mm gravel at a 50mm depth covers roughly 12 m² per tonne, but a driveway's recommended 75-100mm depth needs proportionally more tonnage per m² than a shallower path or border depth. Enter your own dimensions above for an exact figure.

You can, but most UK aggregate supplier and landscaping guides don't recommend it for a driveway - without a compacted sub-base, gravel tends to sink into the ground over time, especially under vehicle weight, meaning you'll need to top it up more often and it will never sit as firm or level as a properly built-up driveway. A sub-base is a bigger upfront cost but saves ongoing maintenance.

A permeable weed-suppressant membrane laid between the sub-base and the gravel layer is commonly recommended - it stops weeds growing up through the gravel while still letting water drain through, and it also helps keep the gravel and sub-base layers separate so they don't mix together over time. It isn't calculated by this tool since it doesn't change your gravel or sub-base quantities.

No - this calculator only prices the gravel and sub-base aggregate itself. Edging (gravel grids, timber or metal restraint edging), a dropped kerb, and any groundworks like excavation or removing an old surface are separate costs not included here.

10% is a commonly used default that covers typical spillage, compaction loss, and minor over-dig. Use a higher margin (15%) for an irregularly shaped driveway, rougher or sloped ground, or if you want a comfortable buffer rather than an emergency mid-job trip to the merchant.

This calculator assumes a simple rectangular driveway (length x width). For an L-shaped, curved, or otherwise irregular driveway, split it into two or more rectangles, calculate each separately, and add the resulting bag counts together - or use the largest bounding rectangle as a conservative over-estimate if the shape is only slightly irregular.

Usually not for resurfacing an existing driveway with permeable gravel, but rules depend on the driveway's size, whether it's a new area of hardstanding at the front of a house, and whether it drains permeably or towards a public road - this varies by local planning authority and isn't something a materials calculator can determine for you. Check gov.uk's planning permission guidance or your local council's planning department before creating a new driveway area.

With an adequate depth and a properly compacted sub-base, a gravel driveway can last many years before needing a significant top-up, though some gradual loss (gravel migrating to edges, being tracked onto roads or paths) is normal and typically addressed with periodic raking and occasional top-ups rather than a full re-lay.

Loose gravel at an adequate depth (75-100mm+) over a proper sub-base copes reasonably well with normal car use, but very heavy or very frequent vehicles (delivery lorries, campervans parked long-term) benefit from a deeper gravel layer (closer to 100mm) and a more substantial sub-base - check with a professional if your driveway needs to handle unusually heavy or frequent loads.

You can, though most UK driveway installations use a single aggregate type for a consistent appearance and predictable coverage. If you do want to mix types (e.g. a border of one aggregate around a different main area), calculate each area separately with its own density for an accurate total.

No. It estimates materials from widely used UK trade depth and density guidance for a standard domestic gravel driveway. It is not a substitute for a groundworks professional's assessment on poor or unstable ground, drainage design, or planning permission considerations, which depend on your specific project and local authority.