Concrete takeoff from plans: calculate and review cubic yards
A concrete takeoff turns the dimensions and notes on a plan set into quantities for a bid. Start with the right revision, calculate each pour separately, and verify the units and scope before you ask a supplier for a price.
Published November 3, 2026 · Illustrative calculation, not a project estimate.
Gather the sheets and scope
Review the current foundation and structural sheets, sections, schedules and general notes. Record the revision, sheet and detail reference, concrete type, thickness or depth, and which slabs, footings, pads or walls belong in the bid. Mark unresolved dimensions and conflicts for the designer or project team instead of silently filling them in.
Calculate slab concrete in cubic yards
For a rectangular slab with consistent thickness, convert inches to feet, multiply length × width × thickness in feet to get cubic feet, then divide by 27. Subtract openings or deductions only when appropriate to the actual scope, and account separately for thickened edges, footings and other concrete not included in that rectangle.
Illustration: 30 ft × 40 ft × (4 ÷ 12 ft) = 400 cubic feet. 400 ÷ 27 = 14.81 cubic yards net.
A chosen 5% allowance gives 14.81 × 1.05 = 15.56 cubic yards before the supplier's rounding or minimum-order rules. Five percent is an example assumption, not a universal waste rate or instruction to order that amount.
Price what the job actually needs
Keep net volume, allowance and proposed order quantity separate. Ask a supplier for a dated quote for the required mix, location and delivery schedule; confirm minimums, load sizes, short-load charges, pumping, tax and freight. Include reinforcement, forms, excavation, labor, finishing and other scope separately when required. A benchmark price is an estimate reference, not a supplier commitment.
Review before the bid goes out
- Trace each measurement to the current plan sheet and detail.
- Check linear, square and cubic units; look for duplicate or omitted pours.
- Resolve uncertain dimensions, design notes, exclusions and alternates.
- Record the quantity, allowance, source and date of each price, plus the reviewer.
- Reconcile the takeoff against the supplier quote and final scope.
Portravo can help prepare a takeoff for review; concrete scope may be handled by the team. Confirm coverage and check the plan references and quantities yourself. No single confirmed line validates a complete takeoff.