Concrete Volume and Bag Calculator
Estimate concrete volume and whole bags for slabs, cylinders and tubes using an entered product yield.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Combine geometry, an entered allowance and the actual mixed yield of the product being purchased.
Slab V=LWH; cylinder V=πD²H/4; tube V=π(Do²−Di²)H/4; bags=ceil[V(1+allowance)/bag yield]
Worked example
A 3 m × 2 m × 0.1 m slab has 0.6 m³ net volume. With 5% allowance and 12 L yield per bag, 0.63 m³ requires 53 whole bags.
Assumptions and input details
Yield is mixed volume per bag, not bag mass; enter the relevant product data. Allowance is your input, not a universal recommended percentage. Identical items share geometry. This estimates material quantity without specifying concrete strength, reinforcement, formwork, foundation adequacy or structural compliance.
References: QUIKRETE: volume and whole-bag calculations
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
The 36 volume definitions distinguish US liquid, US dry and Imperial measures. Cups carry an explicit definition. Japanese shō is 2401/1331 L and a gō is one tenth of it; the explicitly labelled 180 mL rice cup is separate.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · UK Imperial definitions · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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