calculator.exe is a program which is probably legit. So, if calculator.exe is on your computer, it is probably ok, and will NOT cause problems. Even if your system is virus-free, it is still recommended to purchase a good antivirus with a good detection rate, in order to defend your system against viruses and malware.
This program is usually found on disk in C:\Program Files\WindowsApps\Microsoft.WindowsCalculator_10.1703.601.0_x64__8wekyb3d8bbwe\Calculator.exe.
The MD5 fingerprint for this file is af206f0697314e55857631842a7e1037.
This application does NOT run as a Windows service. This is usually a good sign.
This is a x64 executable. It uses the full capacity of modern CPUs.
calculator.exe appears to have visible windows. This means it doesn't work in a kind of invisible mode. Its operation is clearly shown to you.
The digital signature is missing from this program. The authors did not sign it. This is probably bad.
This application does NOT have an uninstall routine stored in registry.