Primary material
62 bags
80 lb concrete mix
Use the calculated bag count as your buying starting point, then verify yield and pallet limits with the store.
Concrete curb calculator
Concrete curb calculator for garden, driveway, and sidewalk edges.
Enter curb length, width, height, and waste allowance to estimate cubic yards, bag count, and rough material cost for a rectangular curb section.
20 ft x 6 in x 6 in
0.20 yd³
10 bags at 80 lb
Formula
L x W x H
Width/height converted to feet
Best for
Curbs
Garden edges, driveway curbs, sidewalk edges
Quick curb answers
Common curb runs
20 ft garden curb
20 ft x 6 in x 6 in
0.20 yd³
10 bags at 80 lb with default 10% waste
40 ft driveway curb
40 ft x 8 in x 8 in
0.72 yd³
33 bags at 80 lb with default 10% waste
60 ft sidewalk edge
60 ft x 6 in x 8 in
0.81 yd³
37 bags at 80 lb with default 10% waste
Profile matters
This calculator assumes a rectangular curb. For curb-and-gutter, rounded faces, or tapered profiles, split the shape into simple pieces and add them together.
Shopping list
Ready to price and order
Use the calculated quantities as a starting cart, then compare store availability, delivery fees, pallet limits, and local ready-mix minimums before buying.
Large pours
Ready-mix quote check
For high bag counts, compare the bagged route against local ready-mix minimums, delivery, access, and unload time.
Optional base
Gravel base
Base depth is project-specific. Estimate it separately before adding bags or bulk gravel to the order.
Optional forms
Forms and stakes
Plan lumber, stakes, screws, release, and bracing around the perimeter and any step-downs or curves.
Store buttons open retailer search results for now. Confirm exact product yield, pickup, delivery, and pallet rules before ordering.
Formula shown
How the curb calculation works
1. Convert width and height to feet
width ft = width in / 12; height ft = height in / 12
2. Calculate curb volume
cubic feet = length ft x width ft x height ft
3. Add waste and estimate bags
bags = ceil(cubic feet x (1 + waste) / bag yield)
Curb edge cases
Curves, gutters, aprons, thickened ends, and complex curb profiles should be estimated separately. Forms, base, stakes, reinforcement, and finishing supplies are not included in the concrete quantity.
Sources
- Quikrete product yields — bagged concrete mix yield references
- Sakrete bagged concrete references — common bag sizes and concrete mix guidance
- ConcreteNetwork concrete price guide — ready-mix and installed concrete cost context
Reviewed for estimating accuracy
Last updated: June 20, 2026
Estimate only.
This calculator is not a quote. Verify product yield, price, delivery minimums, and local conditions with your supplier or contractor before buying materials.
FAQ
Concrete curb questions
Answers for curb volume, curb profiles, bag counts, and material-estimate limitations.
How do I calculate concrete for a curb? + -
For a rectangular curb, multiply curb length in feet by curb width in feet by curb height in feet, then add the entered waste allowance.
How much concrete is needed for a 20 ft curb? + -
For a 20 ft curb that is 6 inches wide and 6 inches high, the calculator estimates about 0.20 cubic yards with the default 10% waste, or about 10 bags of 80 lb concrete mix. The waste percentage is editable.
Can I use this for driveway curbs? + -
Yes for a simple rectangular driveway curb section. If the curb has a gutter, rounded face, tapered profile, or apron, split the shape into simpler pieces or use a project takeoff.
Does this calculator include base gravel or forms? + -
No. It estimates concrete quantity only. Base material, stakes, forms, reinforcement, sealant, and finishing supplies should be estimated separately.
Is this curb estimate a quote? + -
No. It estimates material quantity and rough material cost only. Verify curb profile, reinforcement, subgrade, drainage, and local requirements before pouring.