Concrete Curb Calculator
Calculate the concrete needed for curbing, edging and mow strips.
What you'll need to order
- ready-mix concrete
- form lumber
- stakes
- expansion joint material
- curing compound
Prices vary by region and haul distance. Get quotes from at least two local suppliers.
How this calculator works
cubic yards = length × (width ÷ 12) × (height ÷ 12) ÷ 27
Form lumber is doubled because curbing needs a form on both faces. Where the curb has a batter or a gutter pan, break the profile into rectangles and total them.
Switch the site to metric — the control is in the footer — and your inputs, your results and the tables below follow. The formula, the constants, the guidance text and the sources stay in US units on purpose: that is how the standards they come from are written, and restating them would detach each figure from the document you are meant to be able to check it against.
Where these numbers come from
- NIST Special Publication 811 2008 — the cubic yard as 27 cubic feet
Check the edition. Codes are amended every few years, and the one your inspector works from may not be the one named above.
Worked example
With curb length 100 ft, curb width 6 in, curb height 18 in, this calculator returns 3.06 cu yd.
Waste allowance
The headline figure includes a 10% allowance for waste and over-ordering. The exact requirement is shown alongside it.
Concrete for common curb runs
Every row here opens the calculator already filled in. Copy that link and the numbers travel with it.
| Job | Size | Concrete to order |
|---|---|---|
| Driveway apron edge | 40 ft × 6 in × 12 in | 0.81 cu yd |
| Parking lot curb | 100 ft × 6 in × 18 in | 3.06 cu yd |
| Garden mow strip | 60 ft × 6 in × 6 in | 0.61 cu yd |
| Wide commercial curb | 200 ft × 8 in × 24 in | 10.86 cu yd |
| Short island curb | 20 ft × 6 in × 12 in | 0.41 cu yd |
Frequently asked questions
How much concrete does curbing take?
A 6 by 18 inch curb uses 0.75 cubic feet per linear foot, so 100 ft takes about 2.8 cubic yards. Landscape mow strips at 6 by 6 inches use a quarter of that.
How deep should a concrete curb be set?
At least half its height below grade for stability, and deeper where vehicles will ride over it. A curb that only sits on the surface will tip within a season or two.
Do concrete curbs need expansion joints?
Yes. Tool a control joint every 4 to 6 ft and place a full expansion joint every 20 ft, plus wherever the curb meets a slab or structure. Without them the curb cracks on its own schedule instead of yours.
Can I pour a curb without forms?
Extruded curbing machines do exactly that, but hand-poured curbs need forms on both faces to hold the profile. Stake them every 3 ft — wet concrete exerts far more pressure than people expect.