Increase Calldata Floor Cost

Abstract

This EIP proposes an adjustment to calldata pricing by raising the floor cost from 10/40 to 64/64 gas per calldata byte. This reduces the worst-case block size by ~37% with minimal impact.

Motivation

While EIP-7623 successfully reduced the maximum possible block size by introducing a floor cost of 10/40 gas per byte for data-heavy transactions, continued increases in gas limit demands further optimization. The current floor cost still permits relatively large data-heavy payloads that contribute to block size variance. With 64/64 pricing, a 10 MiB uncompressed execution payload would require ~671M gas instead of ~105M gas under 10/40 pricing, providing significant headroom for gas limit increases.

By increasing the floor cost to 64/64 gas per byte, this proposal aims to:

• Further reduce the maximum possible block size for data-heavy transactions
• Create additional headroom for potential block gas limit increases
• Maintain the same exemption for transactions with significant EVM computation
• Have minimal impact on users

Specification

Parameter	Value
STANDARD_TOKEN_COST	4
TOTAL_COST_FLOOR_PER_TOKEN	16

Let tokens_in_calldata = zero_bytes_in_calldata + nonzero_bytes_in_calldata * 4.

Let floor_tokens_in_calldata = (zero_bytes_in_calldata + nonzero_bytes_in_calldata) * 4.

Equivalently, the floor cost is 64 gas per calldata byte (both zero and non-zero), since TOTAL_COST_FLOOR_PER_TOKEN * 4 = 64. The token abstraction is retained only for consistency with EIP-7623.

Let isContractCreation be a boolean indicating the respective event.

Let execution_gas_used be the gas used for EVM execution with the gas refund subtracted.

Let INITCODE_WORD_COST be 2 as defined in EIP-3860.

The formula for determining the gas used per transaction changes from EIP-7623's implementation to:

tx.gasUsed = (
    21000
    +
    max(
        STANDARD_TOKEN_COST * tokens_in_calldata
        + execution_gas_used
        + isContractCreation * (32000 + INITCODE_WORD_COST * words(calldata)),
        TOTAL_COST_FLOOR_PER_TOKEN * floor_tokens_in_calldata
    )
)

Any transaction with a gas limit below 21000 + TOTAL_COST_FLOOR_PER_TOKEN * floor_tokens_in_calldata or below its intrinsic gas cost (take the maximum of these two calculations) is considered invalid. This limitation exists because transactions must cover the floor price of their calldata without relying on the execution of the transaction. There are valid cases where gasUsed will be below this floor price, but the floor price needs to be reserved in the transaction gas limit.

Rationale

With EIP-7623's implementation, data-heavy transactions cost 10/40 gas per zero/non-zero byte, reducing the maximum possible EL payload size to approximately 1.07 MB (45_000_000/40). This EIP further reduces this to approximately 0.67 MB (45_000_000/64).

By increasing calldata costs from 10/40 to 64/64 gas per byte for data-heavy transactions, this EIP provides:

• Enhanced block size reduction: Maximum data-heavy payload size drops by ~37%.
• Maintained user experience: Regular users engaging in DeFi, token transfers, and other EVM-heavy operations remain unaffected
• Better blob incentivization: Higher calldata costs further encourage migration to blob usage for data availability

The floor cost mechanism ensures that transactions involving significant EVM computation continue to pay the standard 4/16 gas per byte for calldata, preserving the user experience for regular Ethereum operations.

Analyzing the block range 20644414 - 23272414 (Sept. 2024 - Sept. 2025), 1.5% of all transactions would have been affected.

An empirical analysis summarizing the impact of this EIP can be found in this report.

Backwards Compatibility

This is a backwards incompatible gas repricing that requires a scheduled network upgrade.

Wallet developers and node operators MUST update gas estimation handling to accommodate the new calldata cost rules. Specifically:

1. Wallets: Wallets using eth_estimateGas MUST be updated to ensure that they correctly account for the updated TOTAL_COST_FLOOR_PER_TOKEN parameter of 16. Failure to do so could result in underestimating gas, leading to failed transactions.

2. Node Software: RPC methods such as eth_estimateGas MUST incorporate the updated formula for gas calculation with the new floor cost values.

Users can maintain their usual workflows without modification, as wallet and RPC updates will handle these changes.

Test Cases

Testing for this EIP should verify the correct application of the new calldata cost floor of 64/64 gas per byte:

1. Data-heavy transactions: Verify transactions with minimal EVM execution pay the floor cost of 64 gas per calldata byte
2. EVM-heavy transactions: Confirm transactions with significant computation continue using standard 4/16 gas per byte
3. Edge cases: Test transactions at the boundary where execution gas equals or exceeds the floor cost
4. Gas estimation: Validate that eth_estimateGas correctly accounts for the new TOTAL_COST_FLOOR_PER_TOKEN value
5. Invalid transactions: Ensure transactions with insufficient gas limits are properly rejected

Security Considerations

As the maximum possible block size is further reduced compared to EIP-7623, no additional security concerns are introduced beyond those already addressed in the original proposal.

The same transaction bundling considerations from EIP-7623 apply:

1. Transaction bundling was already possible and remains so
2. Bundling does not compromise the block size reduction objectives
3. Practical limitations (trust, coordination) continue to limit widespread bundling

The increased floor cost strengthens the incentive structure for appropriate data availability method selection without introducing new attack vectors.

Copyright

Copyright and related rights waived via CC0.