Fee calculation formula
A Bitcoin transaction fee is approximately its virtual size multiplied by the selected fee rate. The result is rounded up to the next satoshi. Actual relay and replacement policy can vary by node and mempool state.
Free tools / Bitcoin
Bitcoin fee planner
Compare transaction fees and calculate RBF or CPFP targets locally in your browser. No wallet or transaction data is sent to the server.
Compare fee rates
RBF fee bump
Replace-by-Fee creates a replacement transaction that pays a higher fee. The calculation includes a one sat/vB minimum incremental bump.
CPFP package fee
Child Pays for Parent uses a high-fee child transaction so the combined parent and child package reaches a target fee rate.