Concrete Curb Calculator

Calculate the exact volume, weight, and bags needed for your curb and gutter project. Features live 3D visualization and precision engineering calculations.

Thickness of curb top
Vertical face height
Width of gutter section
Depth of gutter section
Base slab thickness
Linear run length
Added for spillage and over-excavation
Enter dimensions to see 3D shape
Total Volume Required –
In Cubic Feet –
Estimated Weight –
60 lb Bags Needed –
80 lb Bags Needed –
With 10% Waste –
  1. Select Units: Choose Imperial (inches/feet) or Metric (cm/meters) at the top.
  2. Measure Dimensions: Enter the Curb Depth, Curb Height, Gutter Width, Gutter Height, and Flag Thickness.
  3. Enter Length: Input the total linear length of your curb run.
  4. Review 3D Shape: Watch the live 3D model update instantly with your exact dimensions.
  5. Check Results: View the total volume, weight, and number of bags required below.

The calculator computes the volume of three distinct sections and sums them:

  • Curb Volume: Curb Depth × Curb Height × Length
  • Gutter Volume: Gutter Width × Gutter Height × Length
  • Flag Volume: (Curb Depth + Gutter Width) × Flag Thickness × Length

Total Volume = Curb Vol + Gutter Vol + Flag Vol. Weight is estimated at 150 lbs/cu ft (2400 kg/m³). Bag counts are derived from total weight divided by bag size.

What is the "Flag Thickness"?
The flag is the flat concrete base slab that extends under both the curb and the gutter to provide structural support.

Why add a waste buffer?
A 10% waste buffer is industry standard to account for spillage, over-excavation, and formwork imperfections. You can adjust this based on your site conditions.