Concrete Curb Calculator
This concrete curb calculator works out how much concrete a curb run needs. Enter the length of the run, the curb height and width in inches, and the number of identical runs, and it gives you cubic yards with your waste allowance, the cross-section, cubic yards per 100 linear feet, the weight and the 40, 60 and 80 lb bag counts. Open the optional cost estimate to price the job by the linear foot.
How to use this calculator
- Enter the length of the run, measured along the face of the curb. On curves, measure along the arc, not straight across.
- Enter the height and width in inches. Use the full depth of concrete you're pouring, not just the part that shows.
- Set the number of runs if you're pouring several runs with the same profile.
- Keep the 10 percent waste allowance. On a narrow curb, spillage and an uneven trench bottom eat a bigger share of the pour than they do on a slab.
Cubic yards = height (ft) × width (ft) × length (ft) ÷ 27
Example: 100 feet of 6 × 6 inch curb
6 inches is 0.5 ft, so the cross-section is 0.5 × 0.5 = 0.25 square feet. Times 100 feet is 25 cubic feet, and 25 ÷ 27 = 0.93 cubic yards. Add 10 percent and you're at 27.5 cubic feet, or 1.02 cubic yards. At 0.60 cubic feet per 80 lb bag (the yield on Quikrete's Concrete Mix data sheet), that's 46 bags.
Concrete per 100 feet of curb
| Section (H × W) | Cross-section | Cubic yards, no waste | 80 lb bags, with 10% waste |
|---|---|---|---|
| 4 × 4 in | 0.11 ft² | 0.41 | 21 |
| 4 × 6 in | 0.17 ft² | 0.62 | 31 |
| 6 × 6 in | 0.25 ft² | 0.93 | 46 |
| 6 × 8 in | 0.33 ft² | 1.23 | 62 |
| 6 × 12 in | 0.50 ft² | 1.85 | 92 |
| 8 × 12 in | 0.67 ft² | 2.47 | 123 |
| 18 × 6 in | 0.75 ft² | 2.78 | 138 |
| 12 × 12 in | 1.00 ft² | 3.70 | 184 |
A quick check on any result: a section of 1 square foot takes 3.70 cubic yards per 100 feet, so yards per 100 feet is just the cross-section in square feet × 3.70. Past about a yard, look at ready-mix (below) or use the concrete bag calculator to compare bag sizes.
What height and width to enter
The form starts at 6 × 6 inches, a common size for residential curb. If you have a city or state detail, use its numbers. TxDOT calls a curb vertical when its face is "6-in or higher" and mountable when it's under 6 inches, with 4 inches or less preferred in some places.
- Height is the whole section, not the reveal. New York City's integral curb shows a 7 inch reveal but is 18 inches deep with a 6 inch top. Enter 18 × 6 and you get 2.78 cubic yards per 100 feet; enter 7 × 6 and you'd order well under half of that.
- Width is the top of the curb. If the back is wider than the top, enter the average of the two.
- Curb with a gutter pan? The pan adds a lot of concrete. Use the curb and gutter calculator instead.
Heights and profiles by agency are in how tall is a curb and types of curbs.
Battered faces and curves
Battered face: reads a little high
The calculator treats the curb as a rectangle, but most street curb leans back. Wisconsin DOT details a batter of 2 inches per foot. On a 6 inch face that's 1 inch of lean, a 3 square inch triangle out of a 36 square inch section, so the rectangle runs about 8 percent high. That's the safe side when you're ordering.
Curves: measure the arc
A 90 degree corner on a 10 foot radius is 15.7 feet of curb, not the 14.1 feet you get measuring straight across. A quarter circle is 1.571 × the radius. Measure curves along the arc or you'll come up short.
Different sections
The number of runs only multiplies identical profiles. If the run changes section, say it drops down at a driveway, run the calculator once for each section and add the yards together.
Bags or ready-mix
A curb is a small volume spread over a long distance. The 100 foot example above takes 46 bags at $8 each, plus a full day of mixing. A plant delivers the same 1.02 yards at about $160 a yard, but a load that small usually carries a short-load or minimum-load charge from the supplier, so ask for it when you get a quote. A curb also has to be poured and struck in one go, which is much easier from a truck.
Bags make sense for a short run, a repair, or a site a truck can't reach. When you call a plant, give them the total cubic yards and the mix. The cost estimate in the calculator starts labor at $4 to $12 per linear foot, with $7 as the middle; the concrete curb cost guide explains the range.
Related calculators and guides
For a curb with a gutter pan, use the curb and gutter calculator. For a footing or a formed wall, use the footing calculator or the wall calculator. For the drive beside the curb, use the driveway calculator. A curb at the street usually means a driveway apron with city rules on thickness and mix. Background on profiles, base and joints is in the concrete curb guide, and how to pour a concrete curb has the steps.
Frequently asked questions
How much concrete do I need for a curb?
Multiply the height by the width in feet to get the cross-section, multiply by the run length in feet, then divide by 27. A 6 by 6 inch curb running 100 feet is 0.93 cubic yards, or 1.02 cubic yards with 10 percent added for waste.
How many bags of concrete for a curb?
A 6 by 6 inch curb 100 feet long needs 46 eighty-pound bags with 10 percent waste, at 0.60 cubic feet per bag. That's about a cubic yard, which is roughly where a ready-mix truck starts to make more sense than bags.
What height should I enter for a curb?
The full depth of concrete you're pouring, not just the part above the road or lawn. A street curb can show 7 inches and be 18 inches deep, and entering only the reveal would leave you well short.
Does this calculator work for a rolled or battered curb?
Yes. It treats the section as a rectangle, so a curb with a sloped face comes out slightly high. A face battered 2 inches per foot on a 6 by 6 inch curb removes about 8 percent of the section, which is the safe direction to be wrong when ordering.
How much does a concrete curb cost per linear foot?
It depends heavily on the job size and the profile. On Arkansas DOT's June 2026 weighted average bid prices, Type B concrete curb came in at $43.00 a foot on a 500 foot job, and Type D at $94.10 a foot on a 99 foot job. Open the cost estimate in the calculator to price your own run with editable material and labor rates.