Curb & Gutter Calculator
Estimate the concrete volume needed for curb and gutter sections. Whether you are planning a driveway transition, street curb, or parking lot drainage channel, this calculator handles the combined curb and gutter cross-section with adjustable dimensions.
Curb Dimensions
Gutter Dimensions
Concrete Output
Bag Counts
Volume Breakdown
How to Calculate Curb & Gutter Concrete
Calculating concrete for a combined curb and gutter section requires treating each part of the cross-section separately.
- Calculate Curb Cross-Section: Convert curb width and height from inches to feet, then multiply. This gives the cross-sectional area of the curb in square feet.Curb Volume (cu ft) = (Width in ÷ 12) × (Height in ÷ 12) × Length (ft)
- Calculate Gutter Cross-Section: Do the same for the gutter width and depth.Gutter Volume (cu ft) = (Width in ÷ 12) × (Depth in ÷ 12) × Length (ft)
- Total Volume: Add the two volumes together. Convert to cubic yards by dividing by 27. Apply 5-10% waste for form overflow and grade variations.
Example Calculation
Standard curb and gutter section — 50 linear feet
- Curb: 6 in wide × 18 in tall = 0.75 × 1.5 = 1.125 sq ft cross-section
- Gutter: 24 in wide × 6 in deep = 2 × 0.5 = 1.0 sq ft cross-section
- Combined volume per foot: 1.125 + 1.0 = 2.125 cu ft per linear foot
- Total for 50 ft: 2.125 × 50 = 106.25 cu ft ÷ 27 = 3.94 cu yd
- With 8% waste: 3.94 × 1.08 = 4.25 cu yd — order 4.5 yards
Common Mistakes in Curb & Gutter Estimation
Ignoring the curb-gutter transition radius
The angled transition between the curb and gutter adds extra volume that simple rectangular calculations miss. Add 5-8% or model the transition as a right triangle for greater accuracy.
Forgetting form overfill and spillage
Curb and gutter pours often have minor form leakage, overfill, and spillage. Unlike slab pours, these forms are narrow and harder to finish cleanly. Always include at least 8% waste.
Mixing up curb height vs total section height
Standard curb height is measured from the gutter flow line, not from the subgrade. Measure from the finished gutter surface to the top of the curb, not from the bottom of the form.
Frequently Asked Questions
How much concrete is needed for a standard curb and gutter?
A standard 6×18 curb with a 24×6 gutter requires about 0.37 cubic yards per 10 linear feet. For 100 feet, plan on 3.7 cubic yards including 5% waste.
What is the standard size of a curb and gutter?
Standard dimensions are curb: 6 inches wide × 18 inches tall, gutter: 24-36 inches wide × 6 inches deep. The combined width is typically 30-42 inches. Local DOT specifications may vary.
How much does curb and gutter concrete cost?
Installed curb and gutter costs $12-$25 per linear foot (2026). Material is $8-$12 per foot for ready-mix concrete. The remainder covers form setup, labor, and finishing. For small DIY projects, bagged concrete may be cheaper.