SettingsSettings for this calculationUS
From the road edge to the far end of the surfaced drive.
Measure along the centreline rather than scaling from a plan, and follow the curves. On a drive that bends, the outside of the curve is longer than the centreline and the fabric has to reach it.
The full width the fabric has to reach across, shoulders included.
Fabric should run out past the edge of the aggregate, not stop level with it, because the shoulder is exactly where a wheel drops off and pumps fines up through an unprotected edge. Add the shoulder width on both sides before entering the figure.
Any surfaced area off the main run, measured rather than estimated.
A hammerhead, a car turning circle, a parking spur and the apron where the drive meets the road are all fabric, and all of them are easier to measure as areas than to describe as a length and a width. They are covered here at the same effective width as the main run.
The manufactured width of the roll you can actually get delivered.
Roll widths differ between suppliers and between product grades, and the difference decides how many passes a drive takes. Confirm the width before ordering rather than after: a narrower roll than assumed can add a whole extra pass down the length of the drive.
How much fabric is on one roll as supplied.
A roll long enough to run the whole drive in one piece saves every end lap on that pass, which is why this figure changes the answer by more than its size suggests. Where the drive is longer than the roll, each following sheet loses a lap to the one before it.
How far each sheet has to overlap the next one, side and end.
AASHTO M 288 sets the minimum against subgrade strength, and the weaker the subgrade the wider the lap it demands — down to the point where sewn seams are required instead of an overlap. Take the figure from the specification for your soil rather than from the last job, and shingle the laps so the upper sheet lies over the lower in the direction traffic runs.
Geotextile rolls required
3 rolls
- Fabric area, laps included
- 10,651.14 ft²
- Effective coverage width per pass
- 11 ft
- Parallel passes across the drive
- 2 passes
- Fabric run to be laid
- 852.09 ft
They open the calculator with your figures already in it
Driveway Separation Geotextile Roll Calculator: 3 rolls — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- AASHTO M 288, Geosynthetic Specification for Highway Applications — the specification that classifies a separation geotextile and sets its overlap and seaming requirements against subgrade strength
- Roll count = ceil(total run length ÷ roll length), where the run is the number of parallel passes across the drive times the drive length plus its end laps, the first pass covers the full roll width and each pass after it adds the width less one side lap — only the joints consume a lap — and a pass covers the roll width less one side lap.
Inputs used
- Drive Length
- 395 ft
- Drive Width
- 14 ft
- Turnarounds, Aprons and Spurs
- 650 sq ft
- Fabric Roll Width
- 12.5 ft
- Fabric Roll Length
- 360 ft
- Required Lap
- 18 in
Intermediate steps
- Fabric area, laps included
- 10,651.14 ft²
- Effective coverage width per pass
- 11 ft
- Parallel passes across the drive
- 2 passes
- Fabric run to be laid
- 852.09 ft
What this calculation does not cover
- Anchor trenches at the apron and at the far end are extra, and so is fabric turned up a shoulder or wrapped around an edge drain.
- Sewn seams, where the specification calls for them on very soft ground, consume a seam allowance rather than an overlap and are not costed here.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Part of a bigger job
Or plan the space itself: measure it once, doors and windows included, and this figure comes back worked out on that space, with what goes with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations2
- AASHTO M 288, Geosynthetic Specification for Highway Applications — the specification that classifies a separation geotextile and sets its overlap and seaming requirements against subgrade strength
- Roll count = ceil(total run length ÷ roll length), where the run is the number of parallel passes across the drive times the drive length plus its end laps, the first pass covers the full roll width and each pass after it adds the width less one side lap — only the joints consume a lap — and a pass covers the roll width less one side lap.
Cite this page
Your workspace
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