# Material Calculators

Within the Plan & Compare Buildings feature, there are several mini-calculators to make it easier to convert units of measure. Sometimes the units that are typically used in preconstruction are not the same as the declared units of product category rules (PCRs) or the units that EC3 will accept for a given material. 

To access the material calculators within EC3, you must first map the collection to the material you would like to calculate. Currently, EC3 has mini-calculators for ready-mix concrete, reinforcing steel (rebar), dimensional lumber, and metal studs (cold-formed metal framing). This user guide will be updated when new mini-calculators are added. 

<figure><img src="/files/2htbdfUH19bIxZL8qyQk" alt=""><figcaption></figcaption></figure>

Once your collection is mapped to one of the materials listed above, click within the quantity cell.&#x20;

<figure><img src="/files/nWtfhEefJHNaQfQPTMd0" alt=""><figcaption></figcaption></figure>

Click on the material calculator you would like to use. Enter your project-specific quantities in the fields according to the calculator you've selected. For example, if you selected "Concrete by Area", enter the area, thickness, and percentage overpour of the concrete you are trying to convert to volume. The result will automatically appear in the cell below "Quantity" and the calculator icon. Click accept to accept the result.&#x20;

<figure><img src="/files/U8YhMBmCMcgdd08Q3qXB" alt=""><figcaption></figcaption></figure>


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