Geotextile Fabric Calculator
Estimate geotextile fabric for a rectangular excavation, aggregate base or drainage area using roll width, side upturns, longitudinal overlaps and end laps rather than treating the project as simple square footage.
Default project preview
1 roll
Required fabric width
14 ft
Fabric strips
2
Total lineal fabric
126 ft
Net protected area
840 ft²
Calculator
Build the material order
Your order will appear here
Enter the project details and calculate a rounded material estimate.
Input and output guide
What each value means
The labels and units below are part of this calculator’s visible methodology. Replace every default with measurements or product data from the actual project.
Covered length
Enter this project assumption in ft. The current imperial default is 60 ft.
Covered width
Enter this project assumption in ft. The current imperial default is 12 ft.
Side upturn at each edge
Enter this project assumption in in. The current imperial default is 12 in. Minimum: 0.
Overlap between adjacent strips
Enter this project assumption in in. The current imperial default is 18 in. Minimum: 0.
End-lap allowance
Enter this project assumption in %. The current imperial default is 5 %. Minimum: 0. Maximum: 25.
Roll width
Enter this project assumption in ft. The current imperial default is 12.5 ft.
Roll length
Enter this project assumption in ft. The current imperial default is 300 ft.
Price per roll
Enter this project assumption in a unitless value. The current imperial default is 290. Minimum: 0.
How to read the outputs
Required fabric width
base width plus both side upturns. Default preview: 14 ft.
Fabric strips
12.5 ft roll width with overlaps. Default preview: 2.
Total lineal fabric
all strips including end-lap allowance. Default preview: 126 ft.
Net protected area
before strip overlaps. Default preview: 840 ft².
Planned fabric area
roll-width layout and end-lap allowance. Default preview: 1,575 ft².
Roll cost
whole rolls. Default preview: $290.00.
Methodology
Transparent calculation
BuildMeter converts every input to a consistent internal unit, applies the selected allowance, and rounds products up to whole purchasable units.
Required width = project width + two side upturns. Effective added width per extra strip = roll width − overlap. Strip count is rounded up; total lineal fabric includes the entered end-lap allowance and is divided by roll length.
Reviewed project guidance
How to use this estimate in a real project
Last reviewed: August 19, 2026
Plan construction geotextile as rolls and strips rather than simple area. The calculator adds side upturns, accounts for overlap between adjacent strips and converts the resulting lineal fabric requirement to whole rolls.
Calculation steps
- 1Measure the plan width that must be separated or filtered.
- 2Add the required fabric upturn at both edges.
- 3Use the specified adjacent-strip overlap to determine effective added roll width.
- 4Calculate strip lengths including end-lap allowance and round total lineal length to whole rolls.
Worked numerical example
A 60 ft by 12 ft aggregate base with 12 in upturns on both sides needs 14 ft of covered width. With 12.5 ft rolls and 18 in strip overlaps, two strips are required. A 5% end-lap allowance makes each strip 63 ft long, or 126 lineal ft total.
Purchasing and rounding
Choose geotextile by its required separation, filtration, drainage or reinforcement properties first; then use the roll calculation. Roll dimensions, seam requirements and overlap can differ substantially among products.
Interpret the result
Planned fabric area is intentionally larger than the net protected area because side upturns and strip overlaps consume material. That difference is functional detailing, not generic waste.
Page-specific assumptions
- Rectangular coverage area.
- Rolls run parallel to the entered project length.
- A uniform overlap applies between adjacent strips.
- End-lap percentage reasonably represents transverse seams and trimming.
Common mistakes
- Treating landscaping weed barrier as an interchangeable construction geotextile.
- Forgetting side upturns in trenches or aggregate bases.
- Using roll area alone without accounting for strip overlap.
- Reducing overlap below the project or manufacturer requirement to save material.
Primary and technical references
BuildMeter provides planning estimates, not engineering, architectural, electrical, mechanical, plumbing, permit or code approval. Review the methodology and verify final decisions with product documentation and qualified professionals.
Related tools
Continue planning the project
BuildMeter Guides
Understand the measurements and assumptions
Use these visible reference guides before changing project inputs or planning allowances.
FAQ
Geotextile Fabric Calculator questions
Is landscape weed fabric the same as construction geotextile?+
Not necessarily. Geotextiles are selected for filtration, separation, drainage or reinforcement properties; use the product specified for the application.
Why include side upturns?+
Trench and aggregate-base details often wrap fabric up the sides so soil cannot migrate laterally into the drainage aggregate.
How much overlap is required?+
Use the project or manufacturer requirement. Soil condition, placement method and whether seams are sewn can change the required overlap.