# Deprecated: Creating Calculators from Spreadsheets

{% hint style="info" %}
ROI Calculators are one of the most usefull features to implement with Flows. Here you will find some tips to generate them more quickly and efficiently.
{% endhint %}

* Calculations take place in Computed Fields.
* Once you have created a **+ New Computed Field** and gave it a Key, you´ll be able to select a Formula Type ---> select **Custom** from the **Select a Formula dropdown.**

![](https://1421794749-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MaGcfSakhqdHaWyb0T_%2F-Mand0dzpqauX_p-3kRB%2F-ManwOVuFgSzjVE52ABt%2Fcustom%20formula.png?alt=media\&token=b07d687b-2d7a-4ccd-89f6-25eadc228b15)

* Select the **User data input fields** that you might need for the calculation and **Generate sample code**

![](https://1421794749-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-MaGcfSakhqdHaWyb0T_%2F-MlW1EiJLbXcbyKrMOvi%2F-MlW3Ckfi58wlbVAnokl%2Fuser_data_and_generate_sample.png?alt=media\&token=598fbafe-d9cd-4be8-954e-e9d8c9f136c9)

* Identify the constant values from the spreadsheets and add them to the code as **const.**
