There are many websites that have integrated a calculator but some give different results by a few units. It isn't anything that we can't calculate ourselves since the tools and information needed are at our disposal:
- Former CM Burchan wrote in a forum post back in April 2018 when Exercise Weapons (250 charges) were being introduced that one unit, 250 charges, would bring a mage exactly from magic level 55 to magic level 56. All online calculators are based on this.
- A mage needs 302494.6 mana (or rounded to 302 495 mana) to advance from magic level 55 to 56. TibiaWiki provides a magic level table that shows some values and explains the formula that has been known and tested as valid.
This magic level (ML) advance formula states that from ML 1 to ML 2 a mage needs 1600 mana spent. Further ML advances need to spend 1.1 times what the previous did. Or to put it in a single line, the needed mana from ML X-1 to ML X is 1600*1.1x-1
The only uncertain part on this formula is the rounding of the mana. If it is rounded to the full value before multiplying by 1.1 to consider the next advancement, higher levels may be off by a small amount but tibia-stats seems to support it isn't, and this would be a small offset anyways.
Adding it all up, the number of 250 charges weapons that you need can be calculated by:
Where X is the desired ML advance, and "mod." stands for "modifier". You can substitute by:
- Modifier 1.1 if training on a private dummy.
- Modifier 2 if training during a double experience and skills event.
- Modifier 2.2 if training on a private dummy during a double experience and skills event.
Note that this helps you calculate the weapons for a single level advance, if you want multiples you just need to keep adding them up. The same applies if you only want 50% of the magic level, just multiple the top part of the fraction by that 50%.
If you want to use weapons with more than 250 charges you can also easily find the result multiplying by Y/250 where Y is the charges of the weapons you will use.
What if I'm not training magic level?
The steps to train magic level for a knight or paladin can be reached reading the TibiaWiki link. Paladins need to substitute the 1.1 in the formula for 1.4, and knights for 3.
As former CM Burchan explained in his answer, and something that is now widely know by players, training a melee skill for a knight, a distance skill for a paladin or a magic level skill for a mage takes the same amount of exercise weapons. So a paladin needs as many weapons to advance from 110 to 111 distance as a mage does to advance their magic level.