Arithmetic operation on Zabbix items

Hi, we are using Grafana with Zabbix plugin as datasource.
In order to monitor cpu usage. Unfortunally, Zabbix item is cpu idle-time, so we need to convert it this way: <CPU_IDLE_TIME> *-1 + 100. When this is done by a query in database (in the case we are acquiring metrics from other tools), we just embed this calculation into the query in Grafana. Now using Zabbix plugin, we cannot see how we can do such thing.
For us is very important to normalize the way cpu usage is shown so it is very important to convert idle time to cpu usage.

Thanks in advance.

How was the problem solved, pls
Thanks in advance.

Hi, I’m just starting to use Grafana, so maybe my solution isn’t perfect, but it seems to work. In the Query menu (where you select Item) add the function “Offset (-100)” and “Scale (-1)”