The Lisk Value Calculator can be used to quickly calculate how much any input amount of Lisk (LSK) is worth at the current market price.

It is available as a Google Chrome extension:

https://chrome.google.com/webstore/detail/lisk-value-calculator/ebbaejiebkagmdfnhmnmffkjmeejpmok

And also a web tool:

https://bluedragon555.github.io/Lisk-Value-Calculator