Project guide
Combine Quantities for Multiple Slabs
Decide whether several pours share one purchase or remain separate orders.
Your measurements
Changing units changes the display, not the stored measurement.
Results
Example inputs
Your result will appear here
Enter the measurements and product details, then calculate.
These tools estimate material quantities from dimensions you choose. They do not specify structural depth or load capacity.
Keep a name and dimensions for every slab
A project total should not erase the individual pours. Record each slab’s dimensions, allowance and concrete specification. Matching products and yields may be combined for purchasing; a different product or bag yield stays separate.
Order timing can also matter to you. PackLedge calculates the quantities you group together; it does not decide when a product should be bought or used.
Example: two small measured pours
Suppose two independent rectangular areas each contain 0.1 m³ of net concrete. One could be 1 m by 1 m by 0.1 m; another could be 2 m by 0.5 m by 0.1 m. These are quantity examples, not recommended slab dimensions.
With a chosen 10% allowance, each requires 0.11 m³. If the user-entered bag yield is 0.012 m³, each separately rounded order needs 10 bags. Two separate orders therefore total 20 bags.
Compare one shared order
The combined unrounded requirement is 0.22 m³. Dividing by 0.012 m³ and rounding once gives 19 bags, supplying 0.228 m³. The example saves one package through aggregation; it does not reduce either slab’s measured requirement.
Choose the grouping you intend to use
A smaller shared count is appropriate only when the product, yield and purchasing arrangements really match. Keep separate groups when they do not. Do not change a product specification merely to force a merge.
Before exporting, check that each source slab appears once and that its allowance has not been added again after grouping. The list should explain both the measured total and the final whole-package purchase.
Frequently asked questions
Why can a combined count be smaller?
A shared order rounds once after adding unrounded requirements. Separate purchases may each need a partly used final bag.
Sources and method
- PackLedge quantity methods
Original derivations using geometry, ratios, sums and whole-package rounding. Each calculator explains its assumptions and worked examples.
- Your selected product label or technical sheet
The source for the coverage, mixed yield, density, package capacity, sheet dimensions or wallpaper repeat that you enter.