French Drain Calculator & Planning Package

Estimate a proposed French drain before requesting quotes or ordering materials.

The French Drain Calculator + Planning Package helps property owners develop preliminary material quantities and project costs for a French drain containing one or multiple segments.

Enter each segment’s length, width, depth, surface-cap depth, pipe outside diameter and fabric overlap. The editable Excel workbook calculates excavation volume, drainage-stone volume and weight, geotextile area, pipe length and segment-level material costs.

Editable assumptions allow you to enter current local prices for stone, pipe, fabric, fittings, outlet protection, delivery, equipment, labor, miscellaneous expenses and contingency. The Summary sheet organizes those inputs into estimated purchasing quantities, total project cost and cost per linear foot.

Two clearly labeled sample segments demonstrate how the calculator works and should be replaced with measurements from your proposed project.

What’s included

• Editable Microsoft Excel calculator
• Capacity for up to 20 drain segments
• Excavation-volume estimates
• Drainage-stone volume and weight estimates
• Geotextile-area estimates
• Pipe-length estimates
• Editable local material and labor costs
• Equipment, delivery and miscellaneous-cost inputs
• Contingency calculation
• Estimated project total and cost per linear foot
• Field-planning checklist and notes page
• Six-page PDF planning guide
• Customer README and startup instructions

Who it’s for

• Homeowners preparing a preliminary French-drain estimate
• Rural and lakefront property owners comparing material requirements
• Contractors and property managers developing preliminary budgets
• Customers preparing for supplier or contractor conversations
• DIY planners who want to understand how trench dimensions affect quantities

File formats and compatibility

The package includes an XLSX calculator and a PDF planning guide.

The calculator is designed for Microsoft Excel and uses standard spreadsheet formulas. It may also open in Google Sheets and other modern spreadsheet applications, but formatting and recalculation can vary outside Microsoft Excel.

The planning guide can be printed on standard US Letter paper or viewed on a phone, tablet or computer.

Important limitation

This is a preliminary quantity and budget-planning tool. It does not determine whether a French drain is the correct drainage solution, calculate hydraulic capacity, establish a lawful discharge location or provide engineered system sizing.