Storage Slot Calculator
Calculate Solidity storage slots for variables, mappings, and nested mappings using keccak256.
Solidity Storage Layout Reference
Simple Variables
Stored sequentially starting at slot 0. Each slot is 32 bytes. Multiple small variables can be packed into one slot.
Mappings
The value for mapping(keyType => valueType) at slot p with key k is at: keccak256(abi.encode(k, p))
Nested Mappings
For mapping(k1Type => mapping(k2Type => valueType)) at slot p: compute keccak256(abi.encode(k2, keccak256(abi.encode(k1, p))))
Dynamic Arrays
Length is stored at slot p. Element i is at keccak256(p) + i.