Reviewed, sourced guidance

How this driveway calculator works and where it stops

Published 23 Sept 2026Reviewed 25 Sept 20262 min read

Direct answer

The calculator adds non-overlapping rectangle areas, then applies the order allowance you enter and the shared sub-base depth. Tonnage is calculated only when you provide a density for the chosen aggregate.

This page exists so the calculation can be checked rather than trusted. It states the formula, the assumptions and their version, and the limits of the result.

Key takeaways

Measured area is the sum of the entered rectangle areas, in square metres.
Sub-base volume uses the entered order allowance and depth.
Tonnage uses the density entered for the selected aggregate; otherwise it is omitted.
The England planning prompt uses measured area before the allowance and does not decide permission.
Assumption version 2026-09-25-v6 is reported with every result.

Evidence note

Source-led homeowner information with its scope, limits and commercial status recorded.

View the full evidence note

Produced by: Driveway Calculator
Jurisdiction: Quantity calculations are UK-wide; the front-garden planning prompt covers England only. Rules elsewhere in the UK and restrictions in designated areas are not assessed.
Page scope: The method, assumptions and limits behind the driveway estimates on this site.
Default subject: Driveway area and sub-base estimation, surface comparison, the planning position for hard surfacing, and drainage constraints.
Excludes: Planning applications, submissions or planning authority decisions; Structural, drainage or engineering advice; Contractor recommendation, ranking or referral; Prices, quotations or cost estimates for any specific job; Driveway installation, surfacing or groundworks
Published: 2026-09-23
Reviewed: 2026-09-25
Commercial status: Information publisher only. No contractor is active, no lead capture runs, no enquiries are collected and no affiliate links are present.

The assumptions are versioned and expected to change as better sources are found. Each result reports the version it was produced under.

How this guidance is produced · Correction submission status

Source review cadence

Every source cited on this site carries a dated check and a recheck trigger, so stale evidence is replaced rather than quietly relied on.

Source	Last checked	Recheck	Triggers an early review
GOV.UK, Guidance on the permeable surfacing of front gardens (page updated 2021-11-12; text copyright 2009; observed 2026-09-25)	2026-09-25	every 60 days	Guidance, fee schedule, legislation status or jurisdiction changes; A planning claim on this site changes
Legislation.gov.uk, Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2 Part 1 Class F (observed 2026-09-25)	2026-09-25	every 60 days	Guidance, fee schedule, legislation status or jurisdiction changes; A planning claim on this site changes
Planning Portal, Paving your front garden (observed 2026-09-25)	2026-09-25	every 60 days	Guidance, fee schedule, legislation status or jurisdiction changes; A planning claim on this site changes
GOV.UK, Fees for planning applications (observed 2026-09-25)	2026-09-25	every 60 days	Guidance, fee schedule, legislation status or jurisdiction changes; A planning claim on this site changes
MHCLG, Planning fees from 1 April 2026 (observed 2026-09-25)	2026-09-25	every 60 days	Guidance, fee schedule, legislation status or jurisdiction changes; A planning claim on this site changes
Legislation.gov.uk, draft England planning-fee amendment; planned commencement 2026-12-08, not yet made at observation (observed 2026-09-25)	2026-09-25	every 30 days	The instrument is made, its commencement date changes, or its fee amounts change; Current fee guidance or a related claim changes
GOV.WALES, planning permission for patios and driveways (observed 2026-09-25)	2026-09-25	every 60 days	Guidance, fee schedule, legislation status or jurisdiction changes; A planning claim on this site changes
MyJobQuote new driveway cost guide, UK 2026 prices (observed 2026-09-25)	2026-09-25	every 45 days	Published date, range or estimate scope changes; Cost claims on this site change
Checkatrade, Driveway Costs in the UK (updated April 2026; observed 2026-09-25)	2026-09-25	every 45 days	Published date, range or estimate scope changes; Cost claims on this site change
Materials Market MOT Type 1 product guidance (observed 2026-09-24)	2026-09-24	every 180 days	Product or material guidance changes; A claim tied to this source changes
Armstrongs Group MOT Type 1 guide (published 2026-04-23; observed 2026-09-24)	2026-09-24	every 180 days	Product or material guidance changes; A claim tied to this source changes
BRMCA, Ready-Mixed Concrete practical guide for site personnel (July 2020; observed 2026-09-27)	2026-09-27	every 180 days	Product or material guidance changes; A claim tied to this source changes
Aggregate Industries, Superdrive asphalt care and maintenance guidance (observed 2026-09-24)	2026-09-24	every 180 days	Product or material guidance changes; A claim tied to this source changes
Sika GB, MonoTop-225 Colour Match Rapid product guidance (observed 2026-09-24)	2026-09-24	every 180 days	Product or material guidance changes; A claim tied to this source changes

The formula

Depth entered in millimetres is divided by 1000 so every term is in metres. Add each rectangle area for the total measured area.

The sub-base volume uses the entered order allowance and depth. Tonnage multiplies volume by a density the user supplies for the chosen aggregate.

measured area = sum of each entered rectangle length x width
area with allowance = area x (1 + entered allowance percent / 100)
sub-base volume = area with allowance x (depth in millimetres / 1000)
tonnage = sub-base volume x supplier density (when supplied)

The assumptions

Every number the calculator assumes rather than computes is listed here, so a disagreement can be traced to a specific figure.

No aggregate density is assumed. If you enter one, confirm with the supplier whether it applies to loose or compacted material.

No default order allowance. Enter the supplier or job-specific figure, or use 0 for base quantity only; this calculator does not model compaction.
No default aggregate density or typical sub-base depth is assumed.
Planning prompt: England guidance for hard surfacing between the dwellinghouse's principal elevation and a highway; measured area over 5 square metres.

Sources for this section: GOV.UK, Guidance on the permeable surfacing of front gardens (page updated 2021-11-12; text copyright 2009; observed 2026-09-25)Legislation.gov.uk, Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2 Part 1 Class F (observed 2026-09-25)Materials Market MOT Type 1 product guidance (observed 2026-09-24)Armstrongs Group MOT Type 1 guide (published 2026-04-23; observed 2026-09-24)

What this tool does not do

It does not decide whether a surface is suitable, and it does not decide whether planning permission is needed.

It does not return a price, because a driveway quote covers preparation, labour and drainage that a quantity tool cannot see.

No planning or building control decision.
No structural, drainage or engineering advice.
No contractor recommendation, ranking or referral.
No price, quote or cost estimate.

Next steps

Check the assumptions version on any result you rely on.
No correction submission route is active in this preview; use the cited source and displayed version to check an estimate.