Standard CLI tool to calculate a public key out of a private key
To the best of my knowledge there is no standard CLI utility.
However, there are some tools which seem to be generally accepted, like bitcoin-bash-tools

Alternatively, you can use some script library, such as pycoin (written in Python), or bitcoinjs.

Personally I like Bitcore libraries (Bitcore is not Bitcoin Core, despite their names are similar). They are also written in Javascript.
I wrote a simple library for handling keys/addresses that can be used from the command line with the NodeJS interpreter: https://github.com/frz-dev/btcutils/blob/master/bitcore-keys-utils.js. In your case you can use the getPubKey function, passing the private key object.

Hope this helps