# Using calculated fields with parameters in Amazon Quick
Using calculated fields with parameters

You can pass the value of a parameter to a calculated field in an analysis. When you create a calculation, you can choose existing parameters from the list of parameters under **Parameter list**. You can't create a calculated field that contains a multivalued parameter—those with a multiselect drop-down control.

For the formula, you can use any of the available functions. You can pass the viewer's selection from the parameter control, to the `ifElse` function. In return, you get a metric. The following shows an example. 

```
ifelse(

${KPIMetric} = 'Sales',sum({Weighted Revenue}),

${KPIMetric} = 'Forecast',sum({Forecasted Monthly Revenue}),

${KPIMetric} = '# Active', distinct_count(ActiveItem),

NULL

)
```

The preceding example creates a metric (a decimal) that you can use in a field well. Then, when a user chooses a value from the parameter control, the visual updates to reflect their selection.