How this calculator works
01
Enter a canonical function signature with parameter types and no parameter names.
02
CoinCalcs validates the manual inputs and applies this published model: selector = first 4 bytes of keccak256(canonical function signature)
03
The result is calculated locally in the browser and is not sent to CoinCalcs or a market-data provider.
Formula
The calculation
selector = first 4 bytes of keccak256(canonical function signature)Example
A concrete scenario
The canonical signature transfer(address,uint256) produces the selector 0xa9059cbb.
Sources used
Solidity ABI specificationCanonical signatures and selectorsUser inputsNo live price, wallet, exchange, or protocol request
Privacy: Calculator inputs are processed locally in your browser. CoinCalcs does not receive or store these inputs. Theme and cookie preferences may be stored on this device.
What this estimate cannot guarantee
- Four-byte selectors can collide and do not identify a contract or prove the intended function is implemented.
- The result is only as current and accurate as the assumptions entered in the form.
- The output is educational scenario arithmetic, not financial, investment, tax, legal, or security advice.