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Box Culvert Quantities Estimator

Quantity & Cost — Barrel, Head Wall & Wing Wall

Set the barrel dimensions and standard headwall geometry (parapet, wing walls, apron and toe wall) to calculate quantities of excavation, concrete (OG/UG/Elevated), lean concrete, reinforcing steel and riprap, with costs based on user-defined unit rates or standard local Authority/Department BOQ rates.

by Shahid Pervaiz: pervaiz.shahid@gmail.com
SPAN HEIGHT Cross-section at headwall

Barrel Geometry

Length runs along the waterway (flow direction); span & height are the clear cell opening.

Head Wall, Wing Wall, Apron & Toe Wall

Applied at both ends of the barrel. Skew angle is recorded for the record only — it is not yet used in the volume formulas.

Reinforcement Steel Ratio

Applied to the concrete volume of each structure to estimate steel weight.

Unit Rates

Edit to match your current schedule of rates.

Quantity & Cost Summary

Barrel — per metre & total

Head Wall, Wing Wall, Apron & Toe Wall

About this box culvert quantities calculator

This tool prepares a bill of quantities and cost estimate for a single box culvert. It is aimed at highway and drainage engineers, quantity surveyors and estimators who need structure quantities during detailed design, tender preparation or cost checking. The culvert is derived from its barrel dimensions and standard head wall geometry — parapets, wing walls, aprons and toe walls — and priced against unit rates you control.

What it calculates

What you control

Every unit rate is editable, along with the contingency percentage, currency label and the number of decimal places shown. Change any rate and the result recalculates immediately. Results can be copied as CSV or printed and saved as a PDF.

How to read the output

The summary table lists each pay item against its BOQ reference, quantity, unit, rate and cost. Open the detailed breakdown to see the underlying geometry and quantities for the barrel, the four wing walls, the apron slabs, the toe walls and the riprap at both ends.

Frequently asked questions

What does the box culvert quantities calculator do?

It produces a bill of quantities and cost estimate for a single box culvert. It shows barrel, wing wall, apron slab, toe wall and riprap quantities, each priced against your own unit rates.

Which quantities does the box culvert calculator compute?

Structural excavation, Class A3 concrete split into underground, on ground and elevated, lean concrete, reinforcing steel by weight, and loose riprap Class C.

How are box culvert construction costs calculated?

Each quantity is multiplied by the unit rate you enter for that item, then a contingency percentage is applied on top. Rates, currency, contingency and decimal places are all editable, so the output matches your own schedule of rates.

Can I export the culvert bill of quantities?

Yes. You can copy the summary table as CSV, ready for Excel, or use the print button to save the full result sheet as a PDF.

Can I change the currency and unit rates?

Yes. Every unit rate is an editable field, and the currency label defaults to PKR but accepts any code you type. All results recalculate immediately.