Enchantment Calculator
Pick a bookshelf count and the calculator shows the range each of the three slots can cost in experience levels.
How we calculate
A slot cost is derived from a base value the table rolls separately for each of the three slots. That roll mixes in two random terms and half the bookshelf count rounded down, so the same shelf count gives a slightly different price every time — always within a predictable range.
The three slots take different shares of that base value: the top one roughly a third, the middle roughly two thirds plus one, and the bottom the base value itself but never less than twice the bookshelf count. That is why the bottom slot tops out at thirty levels on a full library.
Counting past fifteen bookshelves is pointless: the formula uses the count capped at fifteen, not the actual number. Shelves also need a one-block gap from the table or the game will not count them at all — this calculator works from the ones already counted.
Sources
checked 18 August 2026
Questions and answers
How many bookshelves do I need for level thirty?
Fifteen. That is the maximum the formula accounts for: the sixteenth shelf and beyond change nothing.
Why is the price different every time at the same shelf count?
The base value includes two random terms that the table rolls afresh for each slot. The cost therefore moves within the range the calculator shows.
What is item enchantability?
It is a property of the material that feeds the internal enchantment cost, not the level number on the table. Higher enchantability means a richer result for the same price — which is why gold enchants so well.
Why does the calculator not show which enchantments I will get?
Picking the actual enchantments depends on the weight and level range of each one. This version computes slot cost only and does not guess the list.
Unofficial tool. Not affiliated with the developers or publishers of Minecraft.