Measure The Cross-Section Before You Pour
Use this Concrete Curb and Gutter Calculator to estimate concrete for straight curbs, combined curb-and-gutter sections, rolled curbs and multiple curb runs. Enter curb length and cross-section dimensions to calculate cubic feet, cubic yards, approximate concrete bags and optional ready-mix material cost.
Calculate straight curbs, curb-and-gutter sections, rolled curb profiles or multiple identical runs. Results remain hidden until you press Calculate.
Estimate a simple rectangular curb using total run length, curb width and curb height.
This mode assumes a constant rectangular curb section. Battered, sloped or radiused curb faces should be modeled with the closest applicable profile.
Estimate a combined vertical curb plus rectangular gutter slab running the same total length.
This mode models the section as curb rectangle + gutter rectangle. If the curb shares part of the gutter thickness, the curb height field should represent only the height above the gutter slab.
Approximate a rounded curb profile as a half ellipse using base width and rise height.
Rolled curb shapes vary. This mode uses a half-ellipse approximation and should be replaced by the actual cross-sectional area when a project detail is available.
Estimate several identical curb-and-gutter runs from one common cross section.
Use this mode only when each run has the same cross section. Different curb profiles should be calculated separately and added together.
Measure the total curb or curb-and-gutter run length.
Use curb width, height, gutter width and gutter thickness.
Convert cross-sectional area × length into ready-mix volume.
Add a local ready-mix rate for a simple concrete cost estimate.
Curb-and-gutter concrete is usually measured as a long linear element with a relatively small cross section. The correct way to estimate quantity is to determine the cross-sectional area of the concrete profile and multiply that area by the total run length.
Use Straight Curb for a simple vertical rectangular curb. Use Curb + Gutter when the section includes a curb on top of or beside a gutter slab. Use Rolled Curb for a rounded curb profile when a half-ellipse approximation is acceptable. Use Multiple Runs when several separate runs share identical dimensions.
Measure the total linear feet of curb to be formed and poured.
Record curb width, curb height, gutter width and gutter thickness.
Select the calculator that most closely matches the formed concrete shape.
Include extra concrete for variation, forms and placement loss.
Review cubic yards, supplier increments and any profile changes before ordering.
For a simple rectangular curb, multiply curb width by curb height to calculate cross-sectional area. Then multiply that area by the total curb length.
Convert curb width and height from inches to feet before calculating cubic feet.
A curb 6 inches wide is 0.5 foot wide, and 8 inches high is about 0.667 foot high. The cross-sectional area is therefore about 0.333 square foot. Over 100 linear feet, the geometric concrete volume is about 33.33 cubic feet, or approximately 1.23 cubic yards.
A common combined section can be estimated as two rectangles: the gutter slab plus the curb area above the gutter. This avoids double-counting the thickness where the curb sits on the gutter slab.
Use actual formed dimensions and divide inch dimensions by 12 to convert to feet.
If the curb face is battered or the gutter has a slope, the exact cross-sectional area can differ from the rectangular approximation. For precise estimating, use the cross section shown on the project details.
Rolled curb profiles are curved rather than rectangular. The rolled-curb mode approximates the curb cross section as one-half of an ellipse. This gives a better estimate than treating the entire width and height as a solid rectangle when the profile is strongly rounded.
This represents half of an ellipse whose full axes are the entered width and height.
Project-specific rolled-curb templates can differ. If the construction drawing provides a true cross-sectional area, use that area instead of the approximation.
Once the cross-sectional area is known, it is easy to determine concrete per linear foot. For example, a 0.5-square-foot section uses 0.5 cubic foot of concrete for every linear foot of run. Multiply that value by total curb length to obtain the overall geometric volume.
This per-foot method is useful when a project has many curb segments with the same section but different lengths. Add the total linear footage first, then multiply by the common volume per foot.
Short curb repairs can sometimes be placed with bagged concrete. The Straight Curb calculator includes approximate bag quantities for common 40 lb, 60 lb and 80 lb bag sizes using generic planning yields. Always verify actual product yield before purchasing.
Long curb-and-gutter projects usually require enough concrete that ready-mix is easier to plan in cubic yards. Check supplier minimum orders, short-load fees and delivery increments when the calculated quantity is small.
Measure the total run length and the cross-section dimensions shown in the curb detail.
Form dimensions, subgrade variation, transitions, returns and placement loss can increase actual concrete use. The calculator provides 0%, 5%, 10% and 15% ordering allowances so you can compare the exact geometric volume with a practical order quantity.
Long, machine-formed curb runs can be relatively consistent, while hand-formed transitions, driveway openings and returns may create more variation. Use project experience and supplier ordering increments when choosing an allowance.
Enter your local ready-mix price per cubic yard to estimate the concrete-material portion of cost. The result does not automatically include excavation, subbase, reinforcement, forms, curb machine setup, labor, joints, finishing, curing, traffic control, delivery surcharges or disposal.
Linear footage must be combined with the curb cross-sectional area to calculate concrete volume.
If the curb sits on the gutter slab, use only the curb height above the gutter when adding the two rectangles.
Rounded profiles usually contain less concrete than a rectangle with the same full width and height.
Driveway openings, curb ramps and corner returns may use different geometry.
Convert cross-section dimensions from inches to feet before multiplying by run length.
This calculator does not verify slope, inlet spacing, gutter capacity or roadway drainage performance.
The calculator uses standard cross-section × length formulas. Its arithmetic is accurate for the dimensions entered, but actual curb sections can contain slopes, radii, batter, keyways, transitions and other shapes that differ from a simple rectangular model.
For concrete technical information, visit the American Concrete Institute and the National Ready Mixed Concrete Association. For general slab, footing, wall or pier quantities, use the Concrete Calculator.
You can return to the Concrete Curb and Gutter Calculator above to compare curb lengths, profiles and ordering allowances before finalizing a concrete order.
Common questions about curb concrete, gutter sections, linear feet, cross-sectional area, cubic yards, rolled curb and material cost.