Concrete Curb Calculator
A concrete curb calculator estimates cubic yards from curb length and cross-section dimensions. This model adds a rectangular curb to an optional rectangular gutter pan and reports volume per 100 linear feet and total concrete. Use full section dimensions, including concrete below grade.
Concrete including allowance
14.58CY
- Cross-section
- 0.750 SF
- CY per 100 LF incl. allowance
- 2.92 CY
Formula: CY = [curb W × H + pan W × T] (in ft) × length ÷ 27, then + waste %
Rectangular section geometry using your dimensions. No material density is used.
How the calculation works
Convert curb width and height from inches to feet, then multiply for its cross-sectional area. Add gutter pan width × thickness, also in feet. Multiply the combined area by run length and divide by 27 for cubic yards.
A 6-inch-wide by 18-inch-high rectangular curb has a 0.75-square-foot section. At 500 linear feet, it contains 13.89 cubic yards before allowance. An example 5% allowance raises that to 14.58 cubic yards. The volume per 100 feet includes the same allowance.
For curb and gutter, enter a pan width that does not overlap the curb rectangle. The model does not account for radii, batter, or a sloped pan, so compare its section with the actual detail. Use the specified cross-sectional area in a separate calculation when the shape differs materially.
Measure each curb type separately, including transitions or sections with different dimensions. This quantity does not include reinforcement, subbase, excavation, or joints. Default dimensions and allowance are examples, not a standard curb design or order requirement.
Reference values
| Quantity | Value | Basis |
|---|---|---|
| Section area | curb W × H + pan W × thickness | all dimensions in feet; no overlap |
| Cubic yards | section area × length ÷ 27 | before allowance |
| CY per 100 LF | section area × 100 ÷ 27 | then apply allowance |
Frequently asked questions
Do I use exposed curb height?
Use the full concrete height, including the portion below grade. Exposed reveal alone understates the section.
How do I calculate straight curb without gutter?
Leave gutter pan width and thickness at zero.
Does CY per 100 LF include waste?
Yes. Both that result and total concrete include the entered allowance. Cross-sectional area does not.
Is the rectangular model exact for every curb detail?
No. Slopes, radii, batter, and overlaps can change the section area. Check the detail and use a separate area calculation when needed.