Result
6.11 cu yd gravel
Plan for about 6.11 cu yd gravel before confirming the drainage design and local site conditions.
- Base trench volume
- 5.56 cu yd
- Perforated pipe length
- 105 ft
- Landscape fabric area
- 440 sq ft
- Total fall
- 1 ft
Estimate only. Confirm measurements, package or equipment specifications, weather and site conditions, buried utilities, drainage and electrical safety, local rules, and an appropriate material or capacity margin before ordering or building. Read the full disclaimer.
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Product fit checklist
Compare French-drain supplies by pipe diameter, perforation style, fabric width and permeability, fittings, cleanout access, slope tools, and the calculated trench length.
Why this matters: the best purchase is the one whose specifications, safety features, quantity, and maintenance needs fit the real job without adding unnecessary extras or risky workarounds.
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Quick answer
With the sample inputs, this calculator returns 6.11 cu yd gravel. Base trench volume: 5.56 cu yd. Use 6.11 cu yd gravel as the first outdoor planning quantity, then check the detailed material, volume, flow, water-use, or cost results and confirm the site conditions before ordering or digging.
Publisher
Published by EverydayCalc Editorial
Our calculator pages are built to show the formula, explain the inputs, provide examples, and highlight assumptions so readers can understand how each result is estimated.
Results are estimates based on the inputs provided and the assumptions shown on this page. For financial, tax, legal, medical, or other high-stakes decisions, verify results with a qualified professional or official source.
How to use this calculator
The calculator converts trench width and gravel depth to feet, finds trench volume in cubic yards, adds a material allowance, and estimates pipe, fabric, and elevation fall.
When to round up
Round up for uneven excavation, fabric overlap, fittings, cleanouts, delivery minimums, settlement, and site-specific drainage details.
When to use this calculator
- Estimating materials before shopping
- Checking project coverage and waste
- Building a simple supply list
Tips for better estimates
- Measure twice and write down the units.
- Check product coverage and package sizes before shopping.
- Add waste for texture, touch-ups, pattern matching, and measurement error.
How this calculator is reviewed
This page is checked for inputs, formulas, examples, assumptions, topic fit, and related links. For this calculator, the review also covers trench length, width and gravel depth, slope, gravel allowance, pipe length, fabric overlap, discharge location, buried utilities, soil conditions, and local drainage rules.
The sample result is covered by automated tests, and the page links to related calculators and, where available, supporting guides so readers can check the assumptions before acting. If a formula, label, or assumption looks off, send the page URL and your inputs through the contact page.
Formula and methodology
Gravel cubic yards = trench volume in cubic feet divided by 27, multiplied by the material allowance; pipe, fabric, and total fall are calculated from drain length and slope.
Result details: This page uses the inputs above to show base trench volume, perforated pipe length, and landscape fabric area in the result area.
Assumptions to check
The key inputs are Drain length, Trench width, Gravel depth, Material allowance, Planned slope. Gravel volume treats the trench as a rectangular prism and fabric as the trench bottom plus both sides; real pipe bedding, cleanouts, fabric overlap, stone size, soil, outlet design, excavation shape, and delivery minimums can change the order.
How this estimate was built
This page converts rectangular trench dimensions to cubic yards, adds the entered material allowance, gives pipe a small length reserve, estimates fabric across the trench bottom and sides, and translates slope percentage into total fall.
Worked example
Example inputs: Drain length: 100 ft; Trench width: 12 inches; Gravel depth: 18 inches; Material allowance: 10 %; Planned slope: 1 %. With those values, the calculator returns 6.11 cu yd gravel. Plan for about 6.11 cu yd gravel before confirming the drainage design and local site conditions.
Project size to estimated materials
| Small room or repair | Measure carefully and buy one practical unit above the estimate |
|---|---|
| Medium project | Check product coverage and round up to full units |
| Large or irregular area | Add a project-specific buffer before buying |
| Patterned or irregular work | Use a larger waste factor before buying |
Example scenarios
- A 100-foot trench that is 12 inches wide with 18 inches of gravel depth has about 5.56 cubic yards of base trench volume.
- Adding a 10% material allowance raises the gravel plan to about 6.11 cubic yards and estimates roughly 440 square feet of landscape fabric.
- A 1% slope over 100 feet gives 1 foot of total fall, but the outlet, soil, utilities, and local drainage rules still need site-specific confirmation.
Quick reference chart
| Sample result | 6.11 cu yd gravel |
|---|---|
| Base trench volume | 5.56 cu yd |
| Perforated pipe length | 105 ft |
| Landscape fabric area | 440 sq ft |
| Total fall | 1 ft |
| Best next step | Compare the result with the measurements, product coverage, full-unit sizes, site conditions, and project instructions before buying supplies. |
FAQs
French Drain Material Calculator questions
Can I use this as a final shopping list?
Use it as a planning estimate, then compare the result with your measurements, product coverage, site conditions, full-unit sizes, and project instructions.
Should I add a safety margin?
Usually yes. Add a buffer for measurement error, damaged material, layout changes, products sold in full units, and the extra material that fits this specific project.
What should I check before buying?
Check measurements, product coverage, package size, prep needs, compatible tools, fasteners, trim pieces, or other supplies the project requires.
Can this replace professional construction advice?
No. For structural, electrical, plumbing, roofing, or safety-critical work, confirm with a qualified professional.
Is the french drain material calculator exact?
No. It is a project planning estimate. Compare it with your measurements, product coverage, site conditions, full-unit sizes, and project instructions.
What inputs matter most?
Drain length, trench width, gravel depth, material allowance, and planned slope determine the estimate.
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Common planning mistakes
Skipping the right project buffer, measuring once, ignoring product limits, and forgetting the extra supplies or prep work that apply to this material.
Cite or embed this calculator
If this calculator helps a blog post, classroom resource, forum answer, seasonal guide, or local planning page, link to the canonical calculator URL so readers can run their own numbers and check the assumptions.
EverydayCalc.org, "French Drain Material Calculator", last updated July 9, 2026, https://everydaycalc.org/calculators/french-drain-material-calculator/Was this calculator helpful?
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