I imagine there is a simple way to do this, but I need to convert a decimal number to a text percentage (0.15 > 15%) to incorporate into a concatenate formula.

In the field you are concatenating it in, you should be able to just insert something like this:

```
... & ({Field with Decimal Percentage} * 100) & "% " & ...
```

Sharing another version:

LEFT(ROUND({Field with Decimal Percentage}*100,2) & “%”,7)