Concrete bag calculator
Calculate complete bags from placement dimensions, an explicit allowance and the mixed yield printed in the product data.
How to use this calculator
How to measure
Measure the rectangular placement and enter the mixed yield for the exact bag size and product. Do not substitute dry bag volume.
Worked example
A 1 × 1 × 0.1 m placement needs 0.1 m³. With a 0.017 m³ mixed yield, ceil(0.1 ÷ 0.017) gives 6 bags and 0.102 m³ purchased yield.
Formula and purchasing method
net volume = length × width × thickness; planned = net × (1 + allowance/100); bags = ceil(planned ÷ mixed yield per bag).
Assumptions
- The placement is rectangular with uniform thickness.
- Bag yield is copied from the exact manufacturer datasheet or label.
Limitations
- Water demand, mixer capacity, strength selection and curing are outside the formula.
- Actual yield can vary with mixing and placement conditions.
FAQ
Can I enter bag weight instead of yield?
No. Products of the same weight can have different mixed yields; use the published yield.
Why is the bag count conservative?
A fraction of a bag cannot satisfy the planned mixed volume, so it is rounded upward.
Sources
Product-specific values must be copied from the exact current label or technical datasheet; linked examples document the method and its limits.
Calculation privacy
Calculations run locally. Form inputs and results stay in your browser.
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