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Concrete & Masonry

Concrete Calculator: Slabs, Footings, Columns, Post Holes & Steps

Choose the concrete shape you are actually measuring, enter its field dimensions, then compare net volume, allowance-adjusted cubic yards and source-backed 60 lb / 80 lb bag planning references without mixing structural design into the quantity calculation.

Maintained by Home Measure Lab Editorial TeamUpdated Method & corrections

Answer first

Estimate concrete volume and purchase basis

Convert slab, footing or other supported concrete geometry into volume, then round purchasing using the actual ready-mix or bag yield basis you plan to use.

Project measurements

Enter the project measurements and product values that control this quantity.

Quick answer path

Start with the minimum project measurements, then read the result immediately. Open Project / Pro inputs, verified product presets and cost planning only when the job needs more detail.

Concrete planning modeQuick keeps the geometry and allowance visible. Pro adds package/cost and reverse-planning inputs.

Visual measurement check

Verify the selected concrete shape before calculating

The diagram follows the selected project shape so slab, footing/wall, round column, post-hole annulus and solid-step measurements stay distinct. It is a proportional planning aid; the numeric fields remain the source of truth. Planning diagram only. Numeric inputs are authoritative; verify field conditions, product instructions and applicable requirements before acting.

Concrete slab measurement diagramSchematic showing slab length, width and thickness. Length Thickness Width 1 identical slab(s)

Diagram ready. Change a measurement to update this preview.

ft
ft
in
count
%
Quick values

Project result

Your concrete quantity plan

See the measured geometry, net and allowance-adjusted concrete volume, cubic-yard order reference, both source-backed premix bag counts and optional entered-price scenarios.

Planning estimate only. Verify product coverage, package size, supplier specifications and project requirements before purchasing.

Open Project Planner →

Your project history

Use actual-use history as a planning cross-check

Completed projects can become a private reference for future estimates. Home Measure Lab never changes the calculator result automatically.

0 saved records

No matching historical records are saved in this browser yet.

Historical-use reference—Shown only when at least 2 same-unit records exist.
Add a manual historical record

Historical actual use is project-specific evidence, not a universal waste factor, coverage rule or purchase recommendation. Keep product instructions and current project conditions controlling.

Project field workflow

Carry this calculation through the project

Record pour segments, thickness checks and delivery notes.

v9 workflow
1 · Measure / recordConcrete Pour Planning Worksheet
2 · CalculateUse this calculator with the field facts you verified.
3 · Save to projectKeep the result with the rest of the browser-local Project Workspace evidence. 4 · Execute / reconcileRecord field checks and actual usage without rewriting the original plan.

Home Measure Lab keeps measurement evidence, calculated plans and field actuals distinguishable. Project links are browser-local unless you explicitly export them.

Field execution geometry

Mark it from one datum, then verify it

Use the execution schedule with the live measurement diagram above. Numeric inputs and calculator results remain authoritative; verify field conditions, product instructions, code and structural requirements before construction or cutting.

Mark-out & execution schedule

    US cost intelligence

    Turn the material plan into a local budget scenario

    Use current supplier and contractor figures from your project. The calculator never invents a local rate or national “live” price.

    Enter a current material subtotal manually when the calculator result does not include priced materials.
    Pre-tax project subtotal$0.00
    Tax$0.00
    Contingency$0.00
    Planning total$0.00
    Materials share0%
    Labor share0%
    Quote − planning totalNot entered
    Open Quote Sanity Check

    Home Measure Lab does not fetch, infer, or publish live local prices in this release. Enter current supplier and contractor figures for the project being evaluated.

    This tool compares user-entered scope and cost components. It does not determine whether a contractor quote is fair, excessive, fraudulent, code-compliant, or complete.

    Verified product comparison

    Compare source-backed product inputs before you calculate

    These are specification differences, not product recommendations or live prices. Select a preset in the calculator only when it matches the exact product you plan to buy.

    Package Registry 2.0 procurement references · 10 source-backed quantity presets

    These rows multiply exact cited package or stock specifications by common planning quantities. They are not live inventory or purchase recommendations.

    Planning quantityDerived referenceSource spec
    1 × 60 lb bag0.45 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    2 × 60 lb bag0.90 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    3 × 60 lb bag1.35 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    5 × 60 lb bag2.25 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    10 × 60 lb bag4.50 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    1 × 80 lb bag0.60 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    2 × 80 lb bag1.20 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    3 × 80 lb bag1.80 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    5 × 80 lb bag3.00 ft³QUIKRETE Concrete Mix · verified 2026-09-22
    10 × 80 lb bag6.00 ft³QUIKRETE Concrete Mix · verified 2026-09-22

    Bagged Concrete

    ProductPublished / derived inputsVerifiedPrimary source
    QUIKRETE Concrete Mix
    60 lb bag    		bag weight lb: 60 · yield ft3: 0.45
    Approximate yield for the cited QUIKRETE Concrete Mix product. Verify the exact bag label before purchasing.    		2026-09-22Manufacturer source ↗
    QUIKRETE Concrete Mix
    80 lb bag    		bag weight lb: 80 · yield ft3: 0.6
    Approximate yield for the cited QUIKRETE Concrete Mix product. Verify the exact bag label before purchasing.    		2026-09-22Manufacturer source ↗

    Choose the right tool

    When to use this calculator

    You need one head-intent concrete quantity tool for a slab/pad, continuous rectangular footing or wall, round column/pier, post hole around a round post, or simple solid equal-step geometry.

    Use a different calculator when

    Use the specialist concrete tools when you need deeper field-layout detail, and use project drawings/qualified design guidance for structural sizing, reinforcement, strength, frost depth, bearing or code requirements.

    Concrete Footing Calculator →Post Hole Concrete Calculator →Concrete Steps Calculator →

    Methodology

    Formula & assumptions

    Selected shape volume

    shape-specific measured geometry

    Slab/rectangular section = L × W × thickness; round column = πr²h; post hole = gross cylinder − round-post displacement; solid steps = stacked rectangular layers.

    Project base volume

    one measured shape × identical quantity

    Use quantity only when the selected shapes/runs truly share the same dimensions.

    Planning volume

    base volume × (1 + extra allowance %)

    Allowance is explicit and applied after measured geometry.

    Bulk order reference

    planning cubic feet ÷ 27

    There are 27 cubic feet in one cubic yard.

    Premix bag reference

    ceil(planning cubic feet ÷ package yield)

    HML shows both cited QUIKRETE Concrete Mix examples and an editable selected-product yield. Verify the exact product label.

    How to measure this project

    First choose the shape that matches the measured concrete mass. Measure each unlike slab, footing/wall run, pier, post hole or stair set separately. For post holes, measure the actual hole diameter/depth and enter round-post diameter only when that displacement belongs in the pour. For solid steps, the model assumes equal rises and treads stacked as full rectangular layers. Use the identical-quantity field only for repeated geometry; otherwise save separate runs and combine the project totals.

    Before you buy materials

    Use cubic yards as a ready-mix quantity reference and the bag counts as source-backed package examples, then verify the specific product yield and selected supplier/product before purchase. Enter a current local material price only when you want a scenario subtotal. Do not treat this quantity tool as structural design or as a substitute for project drawings, local requirements, reinforcement details, supplier minimums, placement access or delivery planning.

    Reference

    Concrete shape and ordering cross-check

    Planning caseGeometry used hereVerify before buying / building
    Slab / padlength × width × thicknessActual thickness, subgrade variation, reinforcement and project requirements.
    Footing / rectangular wallrun × width × depth/heightRequired section dimensions and structural details from the project.
    Round column / pierπ × radius² × heightActual diameter/height and reinforcement/form details.
    Post hole around round posthole cylinder − post cylinderIrregular excavation, post shape, embedment and project requirements.
    Solid stepsstacked equal rectangular layersLandings, voids, nosings, reinforcement and actual stair geometry.
    Premix bagsplanned ft³ ÷ cited product yieldExact mix, package yield, bag condition and label instructions.

    Bag-yield planning depth

    Cross-check common bag yields against slab thickness

    The table uses the same planning references already shown by this calculator: about 0.45 ft³ for a 60 lb bag and 0.60 ft³ for an 80 lb bag. Product-label yield remains authoritative.

    Approximate area covered by one bag at uniform thickness

    Bag planning reference2 in3 in4 in6 in
    60 lb ≈ 0.45 ft³2.70 sq ft1.80 sq ft1.35 sq ft0.90 sq ft
    80 lb ≈ 0.60 ft³3.60 sq ft2.40 sq ft1.80 sq ft1.20 sq ft

    Planning boundaries

    • Use the optional bags-on-hand fields as a reverse planning cross-check, not as proof that the bags match your project specification.
    • Uneven subgrade, spillage and project requirements can make actual consumption differ from uniform-volume math.

    Start from a drawing

    Concrete Takeoff Studio

    Upload a plan or screenshot, calibrate one known dimension, trace the relevant geometry, and save the measured evidence before returning to this calculator for product-specific planning.

    Open takeoff studio

    Source evidence

    Primary references behind key assumptions

    These references document specific assumptions used or discussed on this page. The exact product label, technical data sheet, project drawings and applicable requirements take priority.

    QUIKRETE — Concrete Mix Technical Data Sheet

    Supports: Published approximate yields include 0.45 ft³ for a 60 lb bag and 0.60 ft³ for an 80 lb bag of QUIKRETE Concrete Mix.

    Boundary: Those are product-specific approximate yields; another concrete mix can publish different yield or installation requirements.

    QUIKRETE — Concrete Calculator

    Supports: Bag planning is based on project volume and approximate packaged-product yield, with waste/uneven-subgrade limitations stated separately.

    Boundary: This supports the planning method, not structural design, ready-mix ordering or a universal bag yield.

    Formula & evidence provenance

    Know which part is arithmetic and which part still needs project evidence.

    Method version v13.0. This record does not replace a product label, project drawing, local requirement or professional design decision. See the site-wide method standard →

    Calculation scope

    Convert slab, footing or other supported concrete geometry into volume, then round purchasing using the actual ready-mix or bag yield basis you plan to use.

    Boundary

    Thickness and dimensions control volume; reinforcement, subbase, joints, mix design and structural requirements are separate project decisions.

    Evidence mode

    registered primary/source evidence

    Questions

    Frequently asked questions

    What concrete shapes can this calculator handle?

    The master calculator handles rectangular slabs/pads, continuous rectangular footings or walls, round columns/piers, round post holes with round-post displacement, and simple solid equal-step geometry. Use specialist calculators when you need deeper field layout or a different shape.

    Why are both 60 lb and 80 lb bag counts shown?

    They are transparent planning comparisons using the cited QUIKRETE Concrete Mix approximate yields. The exact product label controls final purchasing.

    Can this calculator size a structural footing or column?

    No. It only estimates concrete volume from dimensions you enter. Structural dimensions, reinforcement, strength and local/project requirements must come from the appropriate design documents or qualified professional.

    Does ready-mix cost include delivery or short-load fees?

    No. The optional scenario multiplies planned cubic yards by the price you enter. Delivery, pumping, taxes, supplier minimums and other fees stay separate.

    Should I combine different slabs or post holes under quantity?

    Only when their geometry is identical. Run unlike dimensions separately so the measurement evidence remains visible.

    Project pack

    Concrete project pack

    Carry concrete quantity into base preparation, vapor barrier, reinforcement takeoff, formwork and purchasing without mixing those scopes into one opaque estimate.

    Concrete Slab Base Gravel CalculatorContinue →Concrete Vapor Barrier CalculatorContinue →Rebar Grid CalculatorContinue →Wire Mesh Sheet CalculatorContinue →Concrete Form Board CalculatorContinue →Concrete Curing Compound CalculatorContinue →
    Embed this calculator on another website

    Use the lightweight Home Measure Lab widget. The embedded tool is noindex and does not add analytics by default; readers can open the full Home Measure Lab calculator for formulas, assumptions and source notes.

    Keep the natural “Powered by Home Measure Lab” attribution inside the widget. Use the built-in brand attribution as provided; no extra link is required.

    Next step

    Keep this project moving

    Follow the measurement into the most useful related reference, calculator or project view.

    Compare bag yield60 lb vs 80 lb Concrete BagsContinue →Carry cost forwardProject EstimatorContinue →Understand the inputConcrete Bag Yield: From Cubic Feet to BagsContinue →Compare a nearby toolConcrete Footing CalculatorContinue →

    Planning guides

    Understand the inputs behind this calculator

    All guides →

    Concrete & Masonry

    Concrete Bag Yield: From Cubic Feet to Bags

    Understand concrete mix yield per bag and use it to convert slab or hole volume into a realistic whole-bag purchase count.

    Read guide →

    Concrete & Masonry

    60 lb vs 80 lb Concrete Bags: Planning by Yield

    Compare common 60 lb and 80 lb concrete mix bag yields and see why the better planning unit is cubic volume per bag.

    Read guide →

    Concrete & Masonry

    Concrete Slab Thickness Planning: Why Inches Change Volume Fast

    See how slab thickness changes concrete volume and why thickness should come from project requirements rather than a generic calculator default.

    Read guide →

    Concrete & Masonry

    How to Measure a Concrete Slab for Volume

    A step-by-step slab measurement method for length, width and thickness, including irregular shapes and thickened sections.

    Read guide →

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