How this calculator works
01
Paste typed-data JSON containing domain, types, primaryType, and message; the tool never requests a signature.
02
CoinCalcs validates the manual inputs and applies this published model: digest = keccak256(0x1901 || domainSeparator || hashStruct(message))
03
The result is calculated locally in the browser and is not sent to CoinCalcs or a market-data provider.
Formula
The calculation
digest = keccak256(0x1901 || domainSeparator || hashStruct(message))Example
A concrete scenario
A permit payload produces a deterministic digest from its domain, types, primary type, and message fields.
Sources used
EIP-712Typed structured data hashing and signingUser 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
- A valid digest does not make a signature request safe; domain, spender, value, nonce, deadline, and verifying contract still require review.
- 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.