How sat/vB becomes a transaction fee
Multiply virtual size by the fee rate. A transaction estimated at 140 vbytes with a fee rate of 8 sat/vB costs approximately 1,120 satoshis. Divide by 100 million to express the result in BTC, then multiply by your BTC/USD assumption for a dollar estimate.
The BTC price affects only the dollar conversion. It does not change the satoshi calculation. This calculator rounds the estimated fee upward to a whole satoshi; your wallet determines the fee and size of the final signed transaction.
Why transaction size varies
A payment can spend several inputs and create several outputs. Input and output types also affect its weight. That is why two payments with the same BTC amount can have different fees. Use the virtual size of the transaction your wallet is actually preparing instead of assuming one fixed size for every transfer.
Virtual bytes account for transaction weight. Raw bytes and virtual bytes are not interchangeable for every transaction format. The calculator expects vbytes, so check the unit shown by your wallet.
What the estimate leaves out
An exchange withdrawal charge is a separate commercial fee and may not equal the network fee. Confirmation also depends on changing mempool demand, transaction policy and miner selection. Enter several fee rates to compare costs, but use your wallet’s current transaction review before signing.
Questions about this tool
Does sending more bitcoin automatically cost more?
Not when the transaction structure and chosen fee rate stay the same. Adding inputs can increase the size, which can increase the fee.
Is the displayed USD fee a live quote?
No. It uses the BTC/USD price you enter. The fee rate is also an explicit assumption.