Fee Rate
blockchain · economics
Transaction fee per unit of size: commonly sat/vB for Bitcoin or sat/byte for Bitcoin Cash. It helps explain miner selection, not a guaranteed wait.
- Also known as
- sat/vB
Miners usually select transactions by highest fee rate to maximize revenue from limited block space. Wallets estimate the minimum sat/vB needed for a target confirmation window.
Fee equals fee rate multiplied by the size measured in matching units. Bitcoin commonly uses virtual bytes; Bitcoin Cash commonly uses serialized bytes. Transaction construction, including input count and script type, affects that size.
Fee rate versus total fee
A 200 vB BTC transaction at 5 sat/vB pays 1,000 satoshis. A 500 vB transaction at 3 sat/vB pays 1,500 satoshis: a larger total fee but a lower fee rate. Transaction dependencies and miner policy also affect selection, so fee rate alone does not guarantee ordering.
Bitcoin's SegWit specification defines virtual size from transaction weight. A sat/vB figure and a sat/byte figure use different denominators; BTC and BCH satoshis also represent different assets. Compare fees within the correct network and unit.
Read why transaction queues and fees rise, then vary demand and fee priority in Blockspace Lab. The lab illustrates the mechanism; use a current wallet estimate for an actual payment.