Numi is a handy calculator app for macOS. It allows to describe tasks the natural way and instantly get an accurate answer. For example,
$20 in euro - 5% discount or today + 2 weeks.You can use JavaScript extensions to add global variables, custom units or functions. Right now only limited set of API is available via JavaScript, but the plan is to open as much API as possible.
One rack unit (U) is 44.45 mm (1.75 inches) and is used to measure rack-mountable equipment.
How many rack units would a Synology RackStation RS4017xs+ measuring 132.3 mm in height take up?
Entering 132.3 mm in server rack in Numi would return 2.98U or 3U.
You can contribute to Numi by making Numi extensions using the official API.