Concrete Curb Calculator

1. Enter the run length in feet.
2. Enter the curb width and curb height in inches, including the part below grade.
3. Add a gutter width and gutter thickness for curb-and-gutter, or leave them 0 for a barrier curb.
4. Set a 10 percent waste allowance and a bag size, then read the cubic yards to order.

Here is what each result line means:

A concrete curb calculator turns the cross-section and length of a curb into the amount of concrete to order. It handles a plain barrier curb and a combined curb-and-gutter, where a flat gutter pan runs alongside the raised curb.

A curb is the same shape along its whole length, so its volume is the end cross-section area times the run. The tool adds the curb and the gutter sections, converts to cubic yards and bags and adds a waste allowance. To size a driveway or path the curb borders, use the concrete slab calculator; for the mix, the concrete mix calculator.

Because a curb keeps the same profile along its length, the job is to find the area of that end profile and multiply by the run. The profile is the raised curb rectangle plus, for curb-and-gutter, the flat gutter rectangle.

1. Convert each curb and gutter dimension from inches to feet by dividing by 12.
2. Multiply curb width by curb height, and add gutter width times gutter thickness, for the cross-section area.
3. Multiply the area by the run length for cubic feet, then add the waste allowance.
4. Divide by 27 for cubic yards and by the bag yield for a bag count.

For the binder in the mix, the cement calculator sizes the cement.

Suppose you are pouring 50 feet of curb-and-gutter: a 6 inch wide, 18 inch high curb with a 24 inch wide, 6 inch thick gutter, at 10 percent waste.

Calculation: the curb area is 0.5 x 1.5 = 0.75 sq ft and the gutter is 2 x 0.5 = 1.0 sq ft, so the section is 1.75 sq ft. Volume = 1.75 x 50 = 87.5 cu ft, or 3.24 cubic yards. Adding 10 percent waste gives 96.25 cu ft, about 3.56 cu yd and roughly 161 eighty-pound bags.

The lesson: a modest-looking curb section adds up over a long run, so order ready-mix for anything past a short stretch.

Cross-section Size

The whole run holds the same section, so the curb and gutter dimensions set the volume per foot. A taller or wider curb lifts the total along the entire length.

Gutter Pan

Adding a gutter can more than double the section, since the flat pan is often wider than the curb. Include it only if you are pouring curb-and-gutter in one section.

Run Length

Length scales the volume one for one. Measure the full run, following curves by their centre line.

Base and Over-pour

Curb is poured against an earth or gravel base that is rarely perfect, so a waste allowance covers the concrete that fills low spots.

The two common forms are sized the same way, but the gutter adds a second section.

For the delivered price of either pour, the concrete cost calculator in the related tools prices it by the yard.

Ordering Concrete for a Curb Run

Size the run in cubic yards and add waste before you order, so a slip-form or hand pour runs without stopping.

Pricing a Short Curb or Mower Strip

For a short edge or garden mower strip, the bag count shows how many bags to buy and whether hand mixing is realistic.

Comparing Curb Profiles

The cross-section area lets you compare how much concrete different curb and gutter sections use per foot before you commit.

1. Using Only the Curb Reveal

The visible reveal is less than the full curb height, which usually extends below grade. Enter the full height, not just the part you see.

2. Forgetting the Gutter

On curb-and-gutter, leaving the gutter at 0 can halve the estimate. Include the gutter width and thickness when you are pouring both in one section.

3. Mixing Up Inches and Feet

Enter the length in feet and the curb and gutter sizes in inches, as the fields are labelled.

4. Measuring a Curve on the Inside

Follow a curved run along its centre line, not the short inside edge, or you will under-measure the length.

5. Treating the Estimate as a Standard

Curb and gutter dimensions, slopes and joints follow your local DOT or municipal standard, not this tool, which only turns a section into volume.

The arithmetic is exact for a constant rectangular section; the usefulness depends on the dimensions and length you enter.

Find the cross-section area from the curb width times height, add the gutter width times thickness if any, then multiply by the run length and divide by 27 for cubic yards. Fifty feet of a 1.75 square foot section is about 3.24 cubic yards before waste.

It depends on the section. A 6 by 18 inch curb with a 24 by 6 inch gutter is a 1.75 square foot section, so 50 feet is about 3.24 cubic yards, or 3.56 with a 10 percent allowance. Enter your own dimensions above for the exact figure.

Enter the full curb height, including the part below grade, not just the visible reveal. A 6 inch reveal often sits on a curb that extends well below the surface, and the concrete fills all of it.

Only if you are pouring a combined curb-and-gutter in one section. Enter the gutter width and thickness for that case; leave them at 0 for a plain barrier curb with no gutter pan.

A 50 foot curb-and-gutter run is roughly 161 eighty-pound bags with waste, which is far too many to mix by hand, so a run that size is ready-mix. The tool gives the bag count for your run and bag size, rounded up.

Yes, about 10 percent. Curb is poured against an earth or gravel base that is rarely perfect, and slip-forming and hand work both lose some concrete, so a margin keeps the run continuous.

Yes. A garden mower strip or edging is just a small barrier curb; enter its width and height and leave the gutter at 0. The bag count then tells you how many bags to buy.

No. The calculation runs entirely in your browser and nothing you enter is stored or sent anywhere.

• QUIKRETE Concrete Mix 1101 data sheet (QUIKRETE; bag yields 0.60, 0.45 and 0.30 cu ft).
• National Ready Mixed Concrete Association (NRMCA; ready-mixed concrete and ordering).
• American Cement Association (American Cement Association; concrete flatwork basics).