In this track: Execution traces and low-level calls
advanced · 4 MIN READ
Gas forwarding and the 63/64 rule
A requested gas amount is subject to forwarding rules.
LET’S PICTURE IT
A manager retains a reserve instead of handing every remaining resource to a subtask.
SEE IT FOR YOURSELF
Calculate and split a manual execution feeStep 1 / 4
This example supplies twenty-one thousand gas used. It is a simple teaching input, not a live estimate of a contract call.
This example supplies twenty-one thousand gas used. It is a simple teaching input, not a live estimate of a contract call.With base ten Gwei, priority cap two and total cap twenty, the effective rate is twelve Gwei per gas.Twenty-one thousand times twelve Gwei gives two hundred fifty-two thousand Gwei, or 0.000252 ETH.The base-fee component is 0.00021 ETH and is burned. The priority component is 0.000042 ETH for the block fee recipient.
Animated local teaching model. No wallet, RPC or live blockchain data. Some labels and hashes are abbreviated for readability.
Subtract the applicable call costs
Forwarding is calculated after relevant costs such as call overhead and memory expansion. The starting transactiongas limit is not the direct forwarding base.
Apply the cap carefully
Under the EIP-150 rule, the cap is the available amount minus its integer quotient by sixty-four. A request above that cap is limited rather than forwarded in full.
Keep value-transfer details separate
Value-bearing calls have additional rules, including a stipend context. A simplified fraction example is not a complete gas calculator for every CALL.
Do not infer post-call safety
Retaining some gas does not prove that later cleanup, decoding or return-data copying can complete. Analyze the work the caller still needs to perform.
Follow the execution
Simplified eligible gas after costs: 64,000
cap = 64,000 - floor(64,000 / 64)
cap = 63,000
Value-transfer details omitted.
A local conceptual trace with explicit assumptions; this is not a trace of a live transaction.
QUICK CHECK · NO PRESSURE
Is the cap computed directly from the original transaction gas limit?
Relevant call costs and current remaining gas matter.