You can determine how many patient records you have in your Genie database at any time by navigating to Open > Patients.
Above the icons at the top of the window you will see the number of patient records that you have and the current user you are logged in as.
Remove inactive patients
To search just the number of active patients (i.e. remove patients that have been marked as inactive), navigate to Records > Search. In the query window that appears, expand the [Patient] table and highlight Inactive, highlight is equal to in the Comparisons area and choose False as your value. Click Query and the patient list will now show as Patient: X of Y Records, with X being the active patients.