Kerb quantity estimator
Turn measured straight runs into an estimated unit count using your product schedule and project-specific allowance.
Estimate only, not a setting-out or design tool
Use straight lengths and the unit length from the selected product schedule. Curves, transitions, returns, corner units, cutting plans, breakage and reuse of offcuts need separate project quantities. The allowance is your input, not a recommended percentage.
Enter each straight run
Use the same product length and unit of measure within each run. Add separate rows for different products or areas.
Enter a run length and the straight unit length from your product schedule.
Download includes your inputs and references. Entries are not stored; save a copy before leaving.
How the estimate works
For each run, the estimator subtracts the deductions you enter from the measured straight length. It divides the net length by the scheduled straight unit length and rounds up to a whole unit. If you enter an extra allowance, the tool rounds that allowance up to whole units as well.
Net length = measured run - deductions
Base units = round up (net length / unit length)
Estimated total = base units + round up (base units x allowance / 100)
Each row is rounded separately. The result does not assume that offcuts can be reused between runs, or that a specified percentage covers every corner, curve, damaged unit or installation condition. Enter a measured straight run and a unit length taken from the actual project schedule. No default product size is assumed.
Worked quantity example
Suppose you measure a 12 m run with a 1.2 m opening and enter a 0.915 m straight unit from a fictional product schedule. You have 10.8 m to cover: 10.8 / 0.915 = approximately 11.80, rounded up to 12 units. If you enter 5% extra, the allowance is 0.6 units, rounded up to one. The estimate is 13 straight units.
These are example inputs, not a standard size or recommended allowance. You still need to schedule specials and confirm cuts, joints and the supplier's product dimensions separately.
Keep non-straight details separate
Returns, radii, dropped kerbs, transitions, specials and corner units may use different products or installation rules. Measure and schedule them separately rather than forcing them into a straight-run calculation. Confirm openings and interfaces with the current drawing before ordering. This page does not set kerb lines, levels, restraint, bedding or concrete details.
Check the order against the work area
Use the result as a quantity cross-check, then compare it with the approved drawings, product schedule, package scope and supplier's unit length. Keep each row tied to its area and product reference. A total number of straight units does not establish that the layout is buildable or that the correct kerb type has been selected.
For sequencing around channels, gullies and surfacing, read kerbs before asphalt. For concrete properties and terminology, see the concrete specification guide.
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