Concrete planning tool
Turn a rectangular pour into a supplier-order quantity. Choose the increment your supplier accepts, then confirm mix design, minimum order, delivery access, schedule, and quote directly.
Supplier-order calculator
Calculate the delivered quantity, then confirm every order condition with your supplier.
Plan responsibly
This project may be subject to local permit, zoning, site, or structural requirements.
Local requirements control: Model-code references do not confirm the code edition, amendments, zoning rules, permit requirements, or site criteria adopted for your project.
Volume is not a mixture specification: An order quantity does not select a compliant concrete mixture or establish placement, consolidation, curing, or protection requirements.
Concrete performance: The IRC contains model-code provisions for specified concrete strength and weathering-related durability where residential concrete provisions apply.
Source: ICC Digital Codes: 2021 IRC Section R402.2 · Reviewed 2026-08-24
Local requirements may differ. A model-code reference does not confirm the code edition, amendments, zoning rules, or permit requirements adopted where the project is located.
2021 IRC, Section R402.2: Concrete performance. Source: ICC Digital Codes: 2021 IRC Section R402.2. Reviewed 2026-08-24.
Local requirements may differ. Verify the adopted code, amendments, zoning rules, and permit requirements with the local authority.
Methodology
Plan Otter converts dimensions to feet, calculates rectangular-prism volume, divides cubic feet by 27, applies the chosen waste percentage, and rounds only the final quantity upward to the supplier increment selected by the user.
This tool focuses on the delivered ready-mix quantity to discuss with a supplier. It does not select a mix design or duplicate the broader slab-planning output.
Ask about minimum orders, short-load charges, accepted ordering increments, truck access, washout, lead time, unloading time, and cancellation terms before ordering.
Uneven grade, form variance, spillage, and handling can change required volume. Select an allowance appropriate to the site and confirm the final quantity with the supplier or contractor.
Worked examples
At 6 inches thick with 10% waste and a 0.25 yd³ increment, the supplier-order quantity is 2.25 yd³.
At 4 inches thick with 10% waste and a 0.25 yd³ increment, the supplier-order quantity is 6.75 yd³.
Common questions
Calculate cubic volume using compatible units, convert cubic feet to cubic yards, apply the selected waste allowance, then round up to an ordering increment accepted by your supplier.
No. Minimums, increments, truck capacities, short-load policies, and delivery charges vary. The increment is user-selected and all supplier constraints must be confirmed directly.
No. Plan Otter does not infer local supplier pricing. Request a delivered quote that covers the mix, delivery, fees, timing, and site conditions.
Mix design depends on structural requirements, exposure, placement, finishing, climate, and local rules. Use project specifications or professional and supplier guidance rather than this volume calculator.
Ready-mix is ordered in supplier-defined increments. The calculator rounds the adjusted volume up to the increment you select so the displayed order does not fall below the calculated requirement.
Sources
Last reviewed: 2026-08-22
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