Concrete Kerb Calculator 2026 - Curb Volume, Bags & Cost Estimator

Multiply the kerb cross-section area (in square feet) by the total run length to get cubic feet, then divide by 27 for cubic yards. For a straight kerb 6 inches tall (0.5 ft), 8 inches wide (0.667 ft), and 100 linear feet long: (0.5 × 0.667 × 100) ÷ 27 = 1.23 cubic yards before waste.

Always add 10% waste for straight runs, or 15% for curved or complex layouts. For curb-and-gutter, add the gutter slab volume (gutter width × flag thickness × length) to the vertical curb volume before dividing by 27. This calculator handles all profile types automatically.

Standard residential concrete kerbs are 6 inches tall with a 6-8 inch base width. Commercial road curb-and-gutter (AASHTO Type B) is 6 inches tall with a 12-18 inch gutter width and 6-inch flag thickness. Parking lot curb stops are typically 84 inches long, 8 inches wide, and 5.5 inches tall.

Dimensions vary by municipality and road classification - always check your local DOT standard drawing before forming. Rollover or mountable curbs used at driveway aprons are typically 4-6 inches tall with a wider 10-12 inch base profile. You can also review standard specifications in our concrete curb calculator.

Residential landscape kerbs use 3000-3500 PSI standard mix. Commercial and municipal road curbs require 4000 PSI minimum per AASHTO M 254. In freeze-thaw climate zones (most of the USA north of I-40), 4000-4500 PSI with 5-7% air entrainment is required to prevent surface scaling and spalling over winter cycles.

Skipping air entrainment is the number-one cause of failed kerbs in northern states. If your project is in a warm climate year-round (South Florida, Southern California, Hawaii), 3500 PSI without air entrainment is acceptable for residential work.

Concrete kerb installation costs in 2026 range from $9-$24 per linear foot for standard residential landscape kerbing (DIY-friendly), up to $47-$58 per linear foot for commercial curb-and-gutter with full excavation, subbase compaction, forming, pour, and finishing. A 100-foot driveway edging kerb typically costs $900-$2,400 installed.

DIY material costs for a straight kerb run about $3-$7 per linear foot (concrete + gravel base). Professional labor adds $6-$17 per linear foot depending on crew size and complexity. Curved runs, sloped grades, and decorative finishes all increase the per-foot cost. Use the cost calculator above for a project-specific estimate.

Residential landscape kerbs under 6 inches tall and away from traffic generally do not require rebar. Commercial road curbs, curb-and-gutter, and any kerb subject to vehicle impact should include #4 rebar at 18-inch spacing per AASHTO standards. DOT projects specify #4 at 12 inches in high-traffic corridors.

Even for DIY residential kerbs, adding a single #3 or #4 bar centered in the cross-section significantly reduces cracking from soil settlement and root intrusion. Rebar adds about $0.80-$1.20 per linear foot in materials and is worth the investment for kerbs expected to last 20+ years.

Kerb and curb refer to the identical structure - a raised or flush concrete edge restraint along a road, driveway, or landscape area. "Kerb" is the British and Australian English spelling; "curb" is standard American English. Both describe the same product with the same construction methods and material requirements.

On US construction drawings and DOT specifications you will always see "curb." Online searches use both terms interchangeably depending on the searcher's background. This calculator uses both spellings so it works for all users. For US road applications, also see our concrete curb calculator with AASHTO cross-section presets.

Concrete kerbs reach initial set in 6-8 hours. Forms can typically be removed after 24 hours without damaging the face. Light foot traffic is safe at 3 days. Vehicle traffic is safe at 7 days (approximately 70% design strength). Full 28-day cure delivers the design PSI strength for load calculations.

Apply curing compound immediately after final finishing, or cover with wet burlap for the first 7 days to prevent surface shrinkage cracking. In hot, dry, or windy conditions, kerbs are particularly vulnerable to plastic shrinkage cracking in the first 2 hours after placement - use a fine water mist before final finishing if bleed water evaporates too quickly.

One cubic yard (27 cubic feet) yields roughly 60-80 linear feet of standard 6-inch tall, 8-inch wide residential kerb. For a 4-inch tall, 6-inch wide landscape garden kerb, one cubic yard covers 135-145 linear feet. For commercial AASHTO Type B curb-and-gutter (6 in curb + 18 in gutter + 6 in slab), one cubic yard covers only 25-35 linear feet because the cross-section is much larger.

A quick rule of thumb: divide 27 by the cross-section area in square feet to get linear feet per cubic yard. Cross-section area = (kerb height × base width) in square feet. For curb-and-gutter, add the gutter slab area to the calculation. Use our cubic yard calculator to verify your cross-section math.