Step 1: find the stack size
Most items stack to 64. Ender pearls, snowballs, eggs, signs and empty buckets stack to 16. Tools, armour, potions and filled buckets don’t stack, so each one takes a slot. The stack size reference has more examples.
Step 2: count the slots
Divide the items by the stack size. The whole number is full stacks; anything left over needs one more slot.
Step 3: count the containers
Divide the slots by the container size and round up: 27 for a shulker box, chest or barrel, 54 for a double chest.
Three worked examples
| Items | Stacks and slots | Shulker boxes | Double chests |
|---|---|---|---|
| 10,000 cobblestone (stacks to 64) | 156 stacks + 16 items = 157 slots | 157 ÷ 27 → 6 | 157 ÷ 54 → 3 |
| 500 ender pearls (stacks to 16) | 31 stacks + 4 pearls = 32 slots | 32 ÷ 27 → 2 | 32 ÷ 54 → 1 |
| 40 iron pickaxes (don’t stack) | 40 slots | 40 ÷ 27 → 2 | 40 ÷ 54 → 1 |
Planning larger storage
- A double chest of full shulker boxes holds 54 × 27 = 1,458 slots: 93,312 items that stack to 64.
- Shulker boxes can’t go inside shulker boxes. Store boxes of boxes in chests, barrels or ender chests instead.
- Bundles hold up to one stack’s worth of mixed items in a single slot, which helps with many small quantities but not with bulk storage.
- Custom stack sizes: since Java Edition 1.20.5, data packs and commands can give an item any maximum stack size from 1 to 99. Use the calculator’s custom size for those.