A curb-and-gutter takeoff is a cross-section multiplied by a run length. The section has two parts: the curb block around the gutter slab, and the gutter pan beside the curb. Enter both parts plus the run length, and this calculator returns the measured concrete volume before any allowance.
The measured volume stays visible on its own. The planning allowance starts at 0%, so the first result is a checkable measurement rather than a result already changed by an extra percentage.
A curb-and-gutter takeoff is a cross-section multiplied by a run length. The section has two parts: the curb block above and around the gutter slab, and the gutter pan beside the curb. Enter both parts plus the run length, and this calculator returns the measured concrete volume before any allowance.
How much concrete does a curb and gutter need?
Multiply the poured cross-section by the run length. A 100 ft run with an 84 in² section needs 58.333 ft³, which is 2.160 yd³. The calculator shows the measured volume first, then applies a planning allowance only when you enter one.
The curb block is curb depth × (curb height + flag thickness). The gutter pan is gutter width × flag thickness. Adding the two areas gives the section; multiplying by the run length gives the volume.
Which measurements do you need?
You need 5 dimensions for one constant section. Measure the section at the formwork or read it from the approved drawing, and record the source with the numbers.
| Dimension | What to measure | Why it matters |
|---|---|---|
| Curb depth | Face of curb to back edge | Sets the width of the curb block |
| Curb height | Top of curb down to top of gutter slab | Sets the exposed curb face |
| Gutter width | Curb face to back edge of gutter, measured beyond the curb only | The concrete under the curb already sits inside the curb block; measuring it again counts that concrete twice |
| Flag thickness | Thickness of the gutter slab | Sets the gutter pan depth and the base of the curb block |
| Run length | Start to end of one constant section | Volume scales directly with length |
Take enough readings to catch a changed section. Inlets, driveway crossings, and radius returns each need their own run. The guide to measuring curb and gutter shows the field readings that feed this calculator.
What formulas does the calculator use?
The calculator builds the cross-section from 2 rectangles, converts the section dimensions to the base length unit, and multiplies by the run length. It keeps full JavaScript precision during the calculation and displays up to 3 decimal places.
Curb block area = curb depth × (curb height + flag thickness)
Gutter pan area = gutter width × flag thickness
Cross-sectional area = curb block area + gutter pan area
Measured volume = cross-sectional area × run length
Planning volume = measured volume × (1 + allowance % ÷ 100)
| Displayed conversion | Relationship | Calculator use |
|---|---|---|
| Square inches to square feet | 144 in² = 1 ft² | Imperial section area |
| Square millimetres to square metres | 1,000,000 mm² = 1 m² | Metric section area |
| Cubic feet to cubic yards | 27 ft³ = 1 yd³ | Imperial measured volume |
| Cubic feet to cubic metres | 1 ft³ = 0.028316846592 m³ | Cross-system check |
| Cubic metres to litres | 1 m³ = 1,000 L | Metric equivalent volume |
NIST Handbook 44 Appendix C supplies the cited volume relationships. Switching units converts the populated dimensions, clears the displayed result, and requires a fresh calculation in the selected units.
Worked imperial example
A straight run is 100 ft long. The section measures 6 in curb depth, 5 in curb height, 12 in gutter width, and 3 in flag thickness.
- Full curb height: 5 + 3 = 8 in.
- Curb block area: 6 × 8 = 48 in².
- Gutter pan area: 12 × 3 = 36 in².
- Cross-section: 48 + 36 = 84 in², or 84 ÷ 144 = 0.583 ft².
- Volume: 0.583 × 100 = 58.333 ft³.
- In cubic yards: 58.333 ÷ 27 = 2.160 yd³. In cubic metres: 58.333 × 0.028316846592 = 1.652 m³.
Measured result: 2.160 yd³ and 58.333 ft³. A user-entered 10% allowance gives a separate planning volume of 2.377 yd³.
Worked metric example
A run is 10 m long. The section measures 150 mm curb depth, 300 mm curb height, 400 mm gutter width, and 150 mm flag thickness.
- Full curb height: 300 + 150 = 450 mm.
- Curb block area: 150 × 450 = 67,500 mm².
- Gutter pan area: 400 × 150 = 60,000 mm².
- Cross-section: 67,500 + 60,000 = 127,500 mm², or 0.1275 m².
- Volume: 0.1275 × 10 = 1.275 m³, or 1,275 L.
Measured result: 1.275 m³ and 1,275 L. The cross-system check reads 45.026 ft³, or 1.668 yd³.
How do you handle inlets, crossings, and section changes?
Calculate each reasonably uniform straight section separately and add the unrounded measured volumes. A curb inlet, driveway crossing, or radius return changes the section, so each one belongs in its own run with its own dimensions on record. Apply a shared allowance only when the same reason and percentage genuinely apply to every included section.
Rolled and mountable curb profiles use a different section model and sit outside this calculator.
Common curb and gutter quantity mistakes
- Measuring gutter width under the curb as well as beside it, which counts the flag concrete twice.
- Entering curb height without adding flag thickness to the curb block.
- Mixing inches and feet in one calculation.
- Averaging one section across an inlet or a changed profile.
- Applying an allowance before recording the measured volume.
- Rounding every section before adding the total.
- Treating a measured volume as a mix design, strength selection, or structural check.
The curb and gutter mistakes guide shows how each error appears in a takeoff and how to fix it.
How should you turn the volume into an order?
The measured volume is the basis for the order, not the order itself. Confirm the supplier's selling unit, minimum load, and rounding rule before committing. Ready-mix plants in the US sell by the cubic yard; confirm the increment and any short-load terms for the project address.
A packaged-concrete plan needs the exact product's mixed yield from its current label or data sheet. Convert the measured volume to whole bags with the Concrete Bags Calculator, which rounds from yield rather than from bag weight.
Quantity planning does not select the concrete mix, strength, air content, reinforcement, or joint layout. The governing drawings and specifications control those decisions; the curb and gutter mix guide explains what a specification typically states. The ordering guide covers scheduling and delivery checks for the pour.
See the concrete quantity planning tools for the sibling calculators in this category.
Questions about curb and gutter quantity
Can this calculator choose the curb section?
It uses the dimensions you enter. Drawings, specifications, and the responsible project person set the section.
Does the result include waste or spillage?
The calculator returns measured volume from geometry. The allowance field applies one user-entered percentage with a project reason you record.
What should you do with a curved or tapered run?
Break it into short straight sections at constant section, calculate each one, and add the unrounded volumes. Keep the section labels with the sketch.
Can the calculator price the pour?
It calculates quantity. Cost needs a current quote for the product, amount, delivery address, access conditions, fees, and quote validity.
Sources and scope
- NIST Handbook 44 (2026), Appendix C: cubic-foot, cubic-yard, litre, and cubic-metre relationships; accessed 24 October 2026.
- NIST Guide to the SI, Appendix B: inch to millimetre and foot to metre definitions; accessed 24 October 2026.
- NIST Handbook 130 (2026): model legal-metrology and method-of-sale context with varying adoption; accessed 24 October 2026.
Source scope: NIST supports the stated conversions and method-of-sale context. The two-rectangle section model is elementary geometry; its arithmetic matches independently published worked examples for this section type. Drawings, specifications, surveys, supplier records, and responsible people control the section dimensions, mix, order, and work plan.
Review note: Calculation logic and independent automated fixtures passed internal review. Saleem Sial is the research and editorial owner. Waseem Sial, External Reviewer and Engineer, is listed for ongoing external review; no completed review date is claimed. The published page is indexable.