Free calculator

Curb & gutter calculator

Curbs and curb-and-gutter — cross-section × run.

Run / length

Curb width

Curb height

Gutter width (0 = none)

Gutter thickness (0 = none)

Waste / spillage allowanceMost pours order 5–10% extra for spillage and over-excavation.

Estimated volume

1.39cubic yards· 1.062 m³· 37.5 ft³

Bag size	Yield per bag	Bags needed
40 lb	0.3 ft³	125
60 lb	0.45 ft³	84
80 lb	0.6 ft³	63
25 kg	0.413 ft³	91
30 kg	0.496 ft³	76

Planning estimate. Bag counts assume the yields above; check the yield printed on your bag, and allow extra for over-excavation and spillage. Structural and load-bearing work must follow your local building code and an engineer's specification.

Premium · cost estimator

What this pour costs

Bag size

Price per bag

Ready-mix price per cubic yard

Bagged

$409.50

63 × 80 lb

Ready-mix

$231.00

1.4 yd³ ordered

Prices are yours to set and stay in this browser. Ready-mix suppliers usually have a minimum load and a short-load surcharge — check before comparing.

Premium · project

Multi-pour project & order sheet

Add this pour to a saved project to total several pours into one order, then print a clean order sheet with the bag counts and yardage to hand your supplier.

Projects are stored in this browser only — nothing is uploaded and there is no account.

Formwork

How the volume is measured

How this calculator works

A curb is a long prism: its cross-section (width × height) times the run. For curb-and-gutter, the flat gutter pan (width × thickness) is added to the cross-section before multiplying by the length.

The volume is then converted to cubic yards (27 cubic feet to the yard) and cubic metres, and divided by each bag's yield to give a bag count — always rounded up, since you cannot buy part of a bag. Bag yields follow the published premix figures: 0.30 ft³ for a 40 lb bag, 0.45 ft³ for 60 lb and 0.60 ft³ for 80 lb, with metric bags scaled from the same mixed density.

Add a waste allowance for anything real: over-excavated trenches, uneven sub-grade, spillage and what stays in the mixer. Five to ten percent is typical; a rough excavation can need more.

Worked examples

Common curb sizes, already calculated

Concrete for a 20 ft curb0.56 yd³25 × 80 lb bags Concrete for a 20 ft curb and gutter0.8 yd³37 × 80 lb bags Concrete for a 50 ft curb1.39 yd³63 × 80 lb bags Concrete for a 50 ft curb and gutter2.01 yd³91 × 80 lb bags Concrete for a 100 ft curb2.78 yd³125 × 80 lb bags Concrete for a 100 ft curb and gutter4.01 yd³181 × 80 lb bags

Other pours

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