🧱 Concrete Curb Calculator

How to Estimate Concrete for a Curb

A curb is a long, narrow run of concrete, so the volume is its cross-sectional area multiplied by its length. Measure the height and width of the curb's profile, then the total distance it runs.

Curb Formula

Divide the result by 27 to get cubic yards. The calculator above does this for you and adds a 10% allowance for waste.

Curb and Gutter

If your curb includes an integral gutter pan, calculate the curb here, then add the gutter separately: gutter width × thickness × length, converted to cubic feet. Add the two volumes together for your total order.

Standard Concrete Curb Dimensions: How Tall, Wide, and Thick?

There is no single "standard" curb — the right profile depends on what the curb is doing. A garden edge that keeps mulch off the lawn is a very different piece of concrete from a barrier curb holding back a parking lot. These are the profiles you'll actually encounter:

The short answers: a residential landscape curb is typically 6 inches tall and 6 inches wide. A street curb face is usually 6 inches high, and the standard reveal — the exposed vertical face above the pavement — is also 6 inches. Widths run 6 inches for a plain curb and 18–24 inches once a gutter pan is attached.

How Deep Should a Curb Be Buried?

Curb height and curb depth are different measurements, and mixing them up is the most common estimating error on this page. The reveal is what shows above grade; the total height includes the buried portion.

As a rule, bury about one-third to one-half of the curb below finished grade — for a 6-inch reveal, form a curb 9 to 12 inches tall overall. In freeze-thaw climates, set the curb on 4–6 inches of compacted gravel so meltwater drains away instead of lifting it. When you enter a height in the calculator above, use the total formed height, not the reveal.

Concrete per Linear Foot by Profile

Curbing is estimated per linear foot. Multiply the figure below by your run length to get cubic feet, then divide by 27 for yards:

The two 0.333 rows are identical on purpose — volume doesn't care which dimension is the height. A curb 8 inches tall and 6 wide takes exactly as much concrete as one 6 tall and 8 wide.

How to Form and Pour a Concrete Curb

Hand-formed curbs are well within DIY range. The work is mostly in the forming — once the concrete is in, you have maybe 45 minutes to get the profile right.

1. Lay out the run. Mark the curb line with stakes and a string, or a garden hose for curves. Check the line from a few angles before you dig; a curb telegraphs every wobble.
2. Excavate the trench. Dig to the total curb height plus 4 inches for base. For a 6-inch reveal with a 4-inch bury, that's a 10-inch curb in a 14-inch trench.
3. Compact a gravel base. Add 4 inches of crushed stone and compact it in thin lifts. This is what keeps the curb from settling and cracking.
4. Set the forms. Stake 2x lumber on both sides, braced every 2–3 feet. For curves, use 1/4-inch hardboard or bender board — it will follow a surprisingly tight radius.
5. Check form height and slope. Level the forms to your finished curb height and confirm any drainage fall along the run before pouring.
6. Add reinforcement. Run one or two lengths of #3 rebar along the curb, centered and held off the base on chairs. Overlap splices about 12 inches.
7. Mix stiff. Use a low-slump mix. A wet, soupy batch will slump out of the profile the moment you strip forms.
8. Place and consolidate. Fill the forms in lifts, rodding the concrete along the form faces to work out air pockets that leave honeycombing.
9. Screed and float. Strike the top off level with the forms, then float the surface smooth.
10. Tool the edges and joints. Round the top edges with an edger and cut contraction joints every 8–10 feet, at least 1/4 of the curb depth.
11. Strip forms early. Curbs are usually stripped after 12–24 hours so the face can be rubbed and patched while the concrete is still green.
12. Cure and backfill. Keep it damp for at least 7 days, then backfill both sides and tamp the soil so nothing undermines the curb.

Pouring a slab in the same project? The Concrete Calculator handles patios, driveways, and footings, and our slab pouring guide covers the full sequence.

Curb Concrete Cost Guide

Concrete curbing is usually priced per linear foot. Continuous "extruded" landscape curbing is a popular DIY and contractor option.

• DIY materials: roughly $1–$3 per linear foot for a small landscape curb
• Professional landscape curbing: $6–$14 per linear foot installed
• Street / structural curb & gutter: $15–$30+ per linear foot installed

Curb Run	Approx. Concrete	DIY Material Cost
50 ft × 6 in × 6 in	~0.5 cu yd	$50–$150
100 ft × 6 in × 6 in	~0.9 cu yd	$100–$300
150 ft × 6 in × 8 in	~1.8 cu yd	$150–$450

Poured, Extruded, or Precast: Which Curb to Build

Before you order concrete, make sure a poured-in-place curb is actually the right answer. Three approaches cover nearly every residential job, and they differ far more in labor than in material cost.

Hand forming is the cheapest by a wide margin and the only practical option for a curb that has to carry load or tie into a slab. The tradeoff is form work — expect the forming to take longer than the pour.

Extruded curbing is what landscape contractors use for those continuous, seamless garden borders. A curb machine presses a very dry mix through a shaped die, so there are no forms at all. It's fast and handles curves beautifully, but the equipment puts it out of reach for a one-off DIY job.

Precast blocks skip concrete entirely. They're the right call for a short bed border where you just want a clean edge, though the seams between units let grass and roots through in a way a continuous pour doesn't.

Base and Subgrade

Whatever method you choose, the curb is only as stable as what's under it. Strip organic topsoil — it compresses and holds water — and replace it with 4 to 6 inches of compacted crushed stone. Compact in 2-inch lifts rather than dumping the full depth at once; a single thick lift stays loose in the middle no matter how long you run the plate compactor.

In frost-prone regions the base does double duty as drainage. Water trapped beneath a curb expands when it freezes and lifts the concrete, which is why a heaved curb almost always traces back to base prep rather than to the mix.

Curb Pro Tips & Mistakes to Avoid

Pro Tips

• Use a stiff mix. A low-slump (drier) mix holds the curb's shape as you form and tool it; a soupy mix slumps and loses the profile.
• Tie the sections together. Run a length of #3 rebar or drive steel pins through the curb to link segments and resist frost heave.
• Dampen the subgrade. Wet the base before placing so the dry soil doesn't pull water out of the mix.
• Joint it. Tool contraction joints roughly every 10 feet and add expansion joints where the curb meets structures or slabs.

Mistakes to Avoid

• Too-wet concrete. Excess water slumps the curb and weakens it — the most common curb-forming mistake.
• No base prep. A soft or frost-susceptible base lets the curb crack and lift.
• Forgetting the gutter volume. On curb-and-gutter, calculate the gutter pan separately and add it to your order.

Frequently Asked Questions

How do I calculate concrete for a curb?

Multiply the curb length (in feet) by its height and width (in feet), which gives cubic feet, then divide by 27 for cubic yards. For a 50 ft run of 6 in × 6 in curb, that's 50 × 0.5 × 0.5 = 12.5 cubic feet, or about 0.46 cubic yards before overage.

How much concrete is in 100 feet of curb?

A 100-foot curb measuring 6 inches high by 6 inches wide contains about 25 cubic feet, or 0.93 cubic yards of concrete. A larger 6 × 8 inch curb of the same length holds roughly 1.2 cubic yards.

What mix should I use for landscape curbing?

A standard 3,000–4,000 PSI concrete mix works for most curbs. Continuous decorative curbing is usually made with a sand-heavy curb mix; bagged high-strength or crack-resistant concrete is fine for hand-formed curbs.

Do I need rebar in a concrete curb?

Short landscape curbs generally don't need rebar, though a length of #3 rebar or steel pins run through the curb adds strength and helps prevent heaving. Structural street curbs typically include rebar per local specs.

How tall is a standard concrete curb?

A standard street curb has a 6-inch reveal — the exposed face above the pavement. Residential landscape curbs run 4 to 6 inches tall, mountable street curbs 4 to 6 inches, and barrier curbs 6 to 8 inches. Add the buried portion and the total formed height is usually 9 to 12 inches.

How wide is a concrete curb?

Plain curbs are typically 6 inches wide, ranging from 4 inches for light garden edging up to 12 inches for a mountable street curb. Add an integral gutter pan and the total width jumps to 18–24 inches.

How thick should a concrete curb be?

Thickness and width are the same measurement on a curb, and 6 inches is the standard. Don't go below 4 inches — a thinner curb cracks under mower wheels and frost. Where vehicles will ride over it, use 8 inches.

How deep should a concrete curb be buried?

Bury roughly one-third to one-half of the curb below finished grade. A 6-inch reveal usually means forming a curb 9 to 12 inches tall overall. Set it on 4 to 6 inches of compacted gravel, especially in freeze-thaw climates.

How many linear feet of curb does a yard of concrete make?

At the standard 6 × 6 inch profile, one cubic yard pours about 108 linear feet of curb. A 4 × 4 inch garden curb stretches to roughly 243 feet per yard, while a heavy 8 × 8 inch curb only gets about 61 feet.

How many bags of concrete do I need for a curb?

A 6 × 6 inch curb needs about 5 bags of 80 lb mix per 10 linear feet (each 80 lb bag yields roughly 0.6 cubic foot). A 50-foot run takes around 23 bags. Past about 1 cubic yard — roughly 40 bags — ready-mix delivery is usually cheaper and far less mixing.

How far apart should curb joints be?

Tool or saw contraction joints every 8 to 10 feet, cut at least 1/4 of the curb's depth. Add full expansion joints wherever the curb meets a slab, driveway, or structure. Concrete will crack; joints decide where.

How long before you can drive over a new curb?

Keep vehicles off for 7 days minimum, and ideally the full 28-day cure before any regular traffic. Forms can usually be stripped after 12 to 24 hours, and light foot traffic is fine after a day or two.

Can I pour a curb without forms?

Only with extruded curbing equipment, which shapes a very stiff mix as the machine moves along the line. Hand-poured curbs need forms — a hand mix will not hold a vertical face on its own.