At the top, pick Chain Lightning, Blizzard or Meteor.
Fill in your own magic attack, INT, level and skill level.
Choose a monster below: its stats and elemental bonus are filled in, and you see how many hits it takes and how much INT you need.
Or enter the monster's magic defense and level difference yourself.
There's a checkbox for magic defense removal, and Element Amplification can be switched on for ice, lightning, fire and poison.
If it's not enough, it shows how much damage you're short and your current chance of a one-hit kill.
If something in the math looks wrong, let me know. If there are other tools you'd like on the web, leave a comment~
The author declares this an original article. Please respect the copyright and do not repost it without the author's permission.