How anvil costs work
Every anvil operation has a target on the left (your item, or a book) and a sacrifice on the right (an enchanted book). The level cost of one step is:
cost = enchantment cost of the sacrifice + prior work penalty of both + 1 if you rename
Enchantment cost
Each enchantment on the sacrifice costs level × multiplier. Books use a lower multiplier than items: Protection IV from a book costs 4 levels, Thorns III costs 12 (multiplier 4). That is why the calculator only ever sacrifices books, never the item.
Prior work penalty
Every item and book remembers how often it went through an anvil. The penalty doubles with each use, and the result of a step gets the higher counter of the two plus one:
| Anvil uses | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
|---|---|---|---|---|---|---|---|
| Penalty (levels) | 0 | 1 | 3 | 7 | 15 | 31 | 63 |
"Too Expensive!"
In survival mode an anvil refuses any single step of 40 levels or more (creative mode has no limit). Because the penalty grows so fast, the order matters: merging books in pairs keeps every counter low, while adding books one by one to the item makes the last steps very expensive.
Java vs Bedrock Edition
- The formula, the penalty and the 39-level limit are the same in both editions.
- Impaling costs ×2 per level on a book in Java but only ×1 in Bedrock.
- Sweeping Edge exists only in Java; Silk Touch can go on shears only in Bedrock.
- Java treats Sharpness, Smite, Bane of Arthropods, Impaling, Density and Breach as one exclusive group; in Bedrock only Sharpness/Smite/Bane and the Mace group exclude each other.
Need the blocks? See how to craft an anvil and an enchanting table.