Convert Core Lightning's perkw estimate into sat/vB
An operator comparing a channel transaction estimate with an external fee display can be off by a factor of four if the weight and virtual-size units are mixed.
Read estimates with an explicit style
Query both styles on the same Core Lightning node. perkw is satoshis per 1,000 weight units. Despite its name, perkb in this RPC is satoshis per 1,000 virtual bytes.
lightning-cli feerates perkw
lightning-cli feerates perkb
Convert a sample before comparing
A rate of 2,500 perkw corresponds to about 10,000 sat per 1,000 virtual bytes, or 10 sat/vB. Rounding of transaction virtual sizes and changes between samples can affect a comparison. These are onchain transaction fee rates and have different units from Lightning forwarding fees.