Why does SSTORE cost so much more than other opcodes?

SSTORE modifies the blockchain's persistent state, which must be stored by every full node forever. Writing to a new storage slot costs 20,000 gas because it increases the state size. Updating an existing slot costs 5,000 gas. This pricing incentivizes developers to minimize on-chain storage.

What is the difference between cold and warm access?

After EIP-2929 (Berlin upgrade), the first time a transaction accesses an address or storage slot, it pays a 'cold' access surcharge (2,600 gas for addresses, 2,100 for storage). Subsequent accesses to the same slot within the same transaction are 'warm' and cost only 100 gas.

How much gas does a typical ERC-20 transfer use?

A standard ERC-20 transfer() typically uses 50,000-65,000 gas, depending on whether storage slots are cold or warm. This includes SLOAD to read balances, SSTORE to update them, and LOG events. The actual cost depends on the token implementation and access patterns.

Gas Cost Calculator

Build EVM opcode pipelines, analyze gas costs by category, and estimate real-world transaction fees.

EVM Opcodes

Quick Recipes

Pre-built opcode sequences

Execution Pipeline

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Gas Meter

Total Gas

Dust (free-ish)

01005005K20K20K+

Cost Breakdown

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Real-World Cost Estimator

Gas Price30 gwei

1 gwei500 gwei

Gas Used

Cost (ETH)

0.00e+0

Cost (USD)

$0.000000

Based on ETH price of $3,500. Actual costs vary with network conditions.

Stack Depth

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Gas Hogs

Most expensive in pipeline

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Opcode Reference

54 opcodes

Name	Hex	Category	Gas	Stack	Description
CREATE	0xf0	Calls/Create	32,000	-3 +1	Create a new contract
CREATE2	0xf5	Calls/Create	32,000*	-4 +1	Create contract with deterministic address
SSTORE	0x55	Storage	5,000*	-2 +0	Store to storage
BALANCE	0x31	Environment	2,600*	-1 +1	Get ETH balance of address
CALL	0xf1	Calls/Create	2,600*	-7 +1	Call another contract
STATICCALL	0xfa	Calls/Create	2,600*	-6 +1	Static call (read-only)
DELEGATECALL	0xf4	Calls/Create	2,600*	-6 +1	Delegate call (use caller's storage)
SLOAD	0x54	Storage	2,100*	-1 +1	Load from storage (cold)
LOG4	0xa4	Logging	1,875	-6 +0	Emit log with 4 topics
LOG3	0xa3	Logging	1,500	-5 +0	Emit log with 3 topics
LOG2	0xa2	Logging	1,125	-4 +0	Emit log with 2 topics
LOG1	0xa1	Logging	750	-3 +0	Emit log with 1 topic
LOG0	0xa0	Logging	375	-2 +0	Emit log with 0 topics
SHA3	0x20	Crypto	30*	-2 +1	Keccak-256 hash
BLOCKHASH	0x40	Environment	20	-1 +1	Get hash of recent block
EXP	0x0a	Arithmetic	10*	-2 +1	Exponentiation (10 + 50/byte)
JUMPI	0x57	Control Flow	10	-2 +0	Conditional jump
ADDMOD	0x08	Arithmetic	8	-3 +1	Modular addition
MULMOD	0x09	Arithmetic	8	-3 +1	Modular multiplication
JUMP	0x56	Control Flow	8	-1 +0	Unconditional jump
MUL	0x02	Arithmetic	5	-2 +1	Multiplication of two values
DIV	0x04	Arithmetic	5	-2 +1	Integer division
MOD	0x06	Arithmetic	5	-2 +1	Modulo remainder
PUSH1	0x60	Stack	3	-0 +1	Push 1-byte value onto stack
PUSH32	0x7f	Stack	3	-0 +1	Push 32-byte value onto stack
DUP1	0x80	Stack	3	-1 +2	Duplicate 1st stack item
SWAP1	0x90	Stack	3	-2 +2	Swap 1st and 2nd stack items
MLOAD	0x51	Stack	3	-1 +1	Load word from memory
ADD	0x01	Arithmetic	3	-2 +1	Addition of two values
SUB	0x03	Arithmetic	3	-2 +1	Subtraction of two values
LT	0x10	Compare/Bitwise	3	-2 +1	Less-than comparison
GT	0x11	Compare/Bitwise	3	-2 +1	Greater-than comparison
EQ	0x14	Compare/Bitwise	3	-2 +1	Equality check
ISZERO	0x15	Compare/Bitwise	3	-1 +1	Check if zero
AND	0x16	Compare/Bitwise	3	-2 +1	Bitwise AND
OR	0x17	Compare/Bitwise	3	-2 +1	Bitwise OR
XOR	0x18	Compare/Bitwise	3	-2 +1	Bitwise XOR
NOT	0x19	Compare/Bitwise	3	-1 +1	Bitwise NOT
MSTORE	0x52	Memory	3	-2 +0	Store word to memory
MSTORE8	0x53	Memory	3	-2 +0	Store byte to memory
MCOPY	0x5e	Memory	3*	-3 +0	Copy memory areas
CALLDATALOAD	0x35	Memory	3	-1 +1	Load 32 bytes of calldata
POP	0x50	Stack	2	-1 +0	Remove top stack item
MSIZE	0x59	Memory	2	-0 +1	Get size of active memory
ADDRESS	0x30	Environment	2	-0 +1	Get current contract address
ORIGIN	0x32	Environment	2	-0 +1	Get transaction origin (tx.origin)
CALLER	0x33	Environment	2	-0 +1	Get caller address (msg.sender)
CALLVALUE	0x34	Environment	2	-0 +1	Get deposited ETH value (msg.value)
GASPRICE	0x3a	Environment	2	-0 +1	Get gas price of transaction
TIMESTAMP	0x42	Environment	2	-0 +1	Get current block timestamp
JUMPDEST	0x5b	Control Flow	1	-0 +0	Mark valid jump destination
STOP	0x00	Control Flow	0	-0 +0	Halt execution
RETURN	0xf3	Control Flow	0	-2 +0	Return output data
REVERT	0xfd	Control Flow	0	-2 +0	Revert and return data

Fun Fact

The term 'gas' was chosen because, like fuel, it powers the Ethereum Virtual Machine but is consumed in the process.

Understanding EVM Gas Costs

Every operation on the EVM has a gas cost that reflects its computational complexity and state impact. Simple arithmetic (ADD, SUB) costs 3 gas, while storage writes (SSTORE) can cost 5,000-20,000 gas. After EIP-2929, the first access to a storage slot or address is "cold" (expensive) while subsequent accesses are "warm" (cheaper). Understanding these costs is key to writing gas-efficient smart contracts.

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