Range explorer
Exact inclusive bounds and width for any of the 160 intervals.
Tools · educational
Five calculators for the search math
Five calculators with exact intervals, explicit units and honest assumptions. Every page is static HTML first: descriptions, forms and caveats read fine without JavaScript, and the computations re-run in your browser only when JavaScript is available. These pages do not run a solver, do not open a wallet, and send nothing anywhere.
Kangaroo work estimator
Expected group operations for a w-bit window, converted to time at your rate.
Probability & EV
What a scanning or window budget is worth: hit chance and expected value.
Compare intervals
Log-scale charts of search space and window containment, with tables.
Address & public-key inspector
Validate a public Bitcoin address or public key. Never a secret.
How to read these tools
Search work is measured in candidate keys for address scanning and in group operations for public-key methods. The two are not interchangeable: a scanned candidate has to be turned into a point and hashed (one HASH160 per candidate), while a kangaroo step is an elliptic-curve group operation. Each tool states its unit on the field and in the result.
Containment is the probability that a key sits inside a chosen window. Solver success is the probability the method finds a key given that it is inside. They are separate inputs here; finishing a run is not proof that the key was in the window, and finishing a kangaroo work budget is not proof that every key in the window was enumerated.
Rewards shown anywhere in these tools are the catalog's nominal allocations, not balances and not market prices. Nothing on these pages queries the network, a wallet, an engine or an exchange, and no page asks for a private key, seed phrase or WIF.
Probabilities use stable arithmetic (log1p/expm1) so very small values keep their magnitude instead of collapsing to zero, and invalid input produces a message rather than a NaN.
Related reading: method notes, scale of the intervals, the 160-record catalog, and the data sheet.