Concrete Curb & Gutter Calculator

What Is Concrete Curb and Gutter?

This concrete curb gutter calculator estimates the volume of concrete needed for any curb and gutter section — a combined concrete structure installed at the edge of a roadway or parking lot. The curb is the raised vertical or sloped face that delineates the road edge and prevents vehicles from driving onto adjacent areas. The gutter is the flat horizontal slab at road level that channels stormwater runoff toward catch basins and storm drains. Together they form a single L-shaped or trapezoidal concrete section poured in one pass.

Standard residential curb and gutter is specified at 4,000 PSI with air entrainment in cold climates and uses a cross-section with a 6-inch curb height, 6-inch curb width, 12-inch gutter width, and 6-inch flag (gutter slab) thickness. Commercial and municipal specifications may call for an 8-inch curb height and wider gutters. Control joints are cut every 10–15 feet to manage thermal cracking, and the gutter surface is sloped at 2% toward drains.

How to Use This Curb and Gutter Calculator

This concrete curb gutter calculator estimates the concrete volume for a curb and gutter section — a combined roadway edge form commonly used in residential streets, parking lots, and commercial driveways. Enter the curb height, curb width, flag thickness, gutter width, and total run length to get cubic yards, cubic feet, and bag counts instantly. For flat slab work alongside the curb, use our concrete calculator or the concrete driveway calculator.

How to Calculate Concrete for Curb and Gutter

A curb and gutter section has an L-shaped cross section made up of two rectangular parts:

1. Curb section — the vertical raised face above the road: curb height × curb width
2. Base / flag section — the full-width gutter slab at road level: flag thickness × (curb width + gutter width)

Add both areas together, multiply by the run length, then divide by 27 to convert cubic feet to cubic yards. Always add a 5–10% waste factor for spillage and over-pour.

Example: 100-Foot Residential Curb & Gutter

Using standard 6-inch dimensions:

• Curb area: 0.5 ft × 0.5 ft = 0.25 ft²
• Base area: 0.5 ft × (0.5 + 1.0) ft = 0.5 ft × 1.5 ft = 0.75 ft²
• Total cross-section: 0.25 + 0.75 = 1.0 ft²
• Volume: 1.0 ft² × 100 ft = 100 ft³ ÷ 27 = 3.70 yd³
• With 10% waste: 4.07 yd³

Curb and Gutter Tips

• Use 4,000 PSI concrete for curb and gutter — it resists freeze-thaw cycles and salt better than 3,000 PSI mixes
• Set grade properly — gutter must slope toward drains; typical cross-slope is 2%
• Control joints every 10–15 ft to prevent random cracking
• Cure with curing compound immediately after finishing — curb forms dry out quickly
• Order 10% extra — waste factor accounts for over-pour at joints and low spots

Curb and Gutter Cost Per Linear Foot

Curb and gutter installation costs vary by region, site conditions, and whether the project is new construction or replacement. Here are typical 2025–2026 cost ranges:

• Concrete material only — $3–$5 per linear foot for standard 6-inch curb and gutter (approximately 0.037 yd³ per linear foot at $130/yd³)
• Installed by a contractor — $15–$30 per linear foot including forming, pouring, and finishing; machine-extruded curb runs $12–$22 per linear foot for runs over 200 feet
• Demolition and replacement — add $5–$10 per linear foot for sawcutting and removing existing curb before pouring new

For a typical 100-linear-foot residential curb and gutter project, expect to pay $1,500–$3,000 fully installed. Municipal projects with machine extrusion bring the per-foot cost down significantly on longer runs. Always get at least three bids and confirm the quote includes subgrade preparation, formwork, and control joints.